I booked a rather good deal, yesterday, on Orbtiz.com.
YYC - MCO (return) for about 400 USD. I later found out that I cannot go there for the original proposed dates, which were Aug 31st - Sept. 3rd. I called Orbitz and wanted to know if I can re-book and what the penalty was. It turns out that they refunded the entire amount (- $6.99USD for fee). That's just fine by me.
Unfortunatly I didn't find a flight good enough on Orbitz.com, so I had to book a MUCH cheapper one on Expedia.ca, which just so happened to have it cheapper.
Anyway, thank you Orbitz. The process took less than 5 minutes. That's the way business should be done. I will book with them again as soon as I have a chance. (As much as I like them, my $$$ are important, so getting the flight cheapper somewhere else is what I had to do).
But again, I recomend this website/company to you guys.