In this particular situation, you have no "rights", as you agreed to the conditions of contract of carriage (the small print provided to you on the back of the boarding pass or ticket, or the insert provided to you by your travel agent or airline). Even if you did not see or read that contract, you are considered to have agreed to it when you purchase the ticket.
With regard to schedule changes, in the USA, the CCC
(condition of contract of carriage) for all carriers is terribly complex; however, it basically comes down to this: When you purchase a ticket, you enter into a contract with an airline to carry you from point A to point B on a specific flight with a specific departure and arrival time. If you fail to perform your obligation under that contract, e.g. travel on that flight or have paid to voluntarily change your flight, then the airline retains the right to declare a de facto breach of contract. In that event, the airline retains the right to void your ticket and keep your money.
As a pratical matter, airlines generally do not void your ticket if you cancel your reservation in advance of departure. However, if you no-show the flight and the seat goes empty, then the airline does have the right to void your ticket. Most US carriers enforce this policy as it relates to no-shows.
Now, looking at the contract from your perspective, the airline has an obligation to carry you from A to B at the time published in their schedule. If they change that schedule, they are required to do one of two things: a) offer you an alternative schedule or b) refund your ticket, if the schedule change occurs before your flight departure. In the event your schedule change comes while you are traveling, the airline has an obligation to contact you and advise you of the schedule change. If they make an attempt to contact and are not able to do so after three attempts, they have met their obligation to contact you regarding the schedule change.
As to options, the airline must offer you an alternate schedule or offer you or book you on another airline at their expense (the old CAB rule 240). A refund is not possible in this situation because refunds are predicated on what fare would be based for the portion actually traveled. Since that is almost always higher than the value of the original ticket, the rule 240 was instituted by the CAB in the 60s to protect passengers from financial loss due to airline schedule changes.
In the majority of cases, airlines are able to accommodate you within a reasonable amount of time on their own services. However (and this is more so on international flights), in some cases, in order to meet their obligation, they have to put you on another airline, or they have not met their obligation under the contract.
Just as an aside, the carrier's contract of carriage requires them to get you from a to b at the schedule published. When the carrier cannot do so because of a situation under which they have control (mechanicals, delays, etc), then they must put you on another airline and/or putting you up at their expense until they can get you out. In cases of events beyond the direct control of the airline: weather, ATC delays, airport emergencies, etc., the carrier would not have an obligation to do anything other than rebook you on another flight on their airline.
...now that I have described this in excrutiating detail, here is how these rules apply to your situation:
You were called in advance of your departure and advised of the schedule change. You were offered an alternate schedule or a refund. While those options may not be acceptable to you, that is the extent of the obligation the airline has with regard to your travel on their carrier. On the way home, you were advised of a schedule change, but you were not given an alternative other than flying on their own trip, which was inconvenient to you. If there was a flight on another airline at or about the time you were originally scheduled to travel and they did not offer that, then 'technically' they would be breach of contract, because they did not offer you that alternative.
If there was no flight other than their own service at the time they stated for the schedule change, then you were offered the only alternative that existed, and at that point, the airline has met their obligation under the contract.
You may have some rights; however, it really doesn't help you much. A portion of the conditions of carriage states that the limit of liability for breach of contract is the reimbursement of the cost of the ticket. This limitation exists because civil law does not permit someone to collect damages for an event that was unintentional as it related to your contract of carriage.
Are you totally confused now?
In other words, you would need to prove that the airline changed their schedule to intentionally inflict damage on you directly. Schedule changes are required for the operation of the airline, therefore you will never collect damages in that particular situation.
So where does that leave you?? Unfortunately for you, it leaves you nowhere. The airline met their obligation to advise you, offer you all possible options and once they have done that, then there is not much you can do.
The worst part of all of this is if people disservice you or treat you badly, there is nothing in the contract of carriage that provides for any remedy for poor service. Their obligation is strictly to take you from a to b at the times stated in their schedule, period.
Now, here is where you can help your situation. Airlines (and other transportation companies) profess they are service companies and have stated what their "customers' rights" are when you fly their airline. The more flying you do, the more influence you have. If you fly over 100K per year and pay full coach or First Class, you will more likely see some form of non-cash compensation as a customer goodwill gesture.
If you fly infrequently, your only option is to vote with your wallet and fly another airline. You cannot go to the press and make noise, because in most cases, the airline will sue you for slander and defamation (yes they do that) if you say anything other than the exact truth (hard to do when talking to the press, because you can be taken out of context very quickly), you are at some risk. It is minor, because the airline will in most cases not sue you unless you hurt them in a malicious way that becomes a big public issue.
Now, some practical advice: Get a travel agent to help you. They will in most cases give you alternatives, so you would have information that would help you in the event of a schedule change and having alternatives in your hip pocket when traveling gives you a certain amount of power to control your situation. Also, you do not have to make an instant decision regarding a schedule change. If you are advised of a schedule change, do not make a decision on the spot. Investigate your options before you make a decision re the schedule change. Lastly, do not schedule yourself tight. Leave sufficient time to cover you in the event you have a schedule change that may create inconvenience. If you don't have to be somewhere at a specific time, you will be in a better position to negotiate yourself into a better situation. NEGOTIATE? Yes. If you know the schedule and you work with the airline reservations agent, in most cases, you can negotiate yourself on another flight that will meet your needs.
In closing, in this time of flux in the airline business, you must expect something to go wrong. When you plan for problems and none happen, you are pleasantly surprised. If something does happen, then you are better prepared to deal calmly with the situation, so that when you deal with the airline, you can deal with them in a calm and rational manner. This last point is the single biggest factor in your ability to get what you want. If you are NICE and work with them, you usually will come out with more than if you are POd at them. At that point, you are at their mercy. Trust me, you don't want to be in that position.
I hope that you find this helpful.
David L. Lamb, fmr Area Mgr Alitalia SFO 1998-2002, fmr Regional Analyst SFO-UAL 1992-1998