No, do NOT do that unless you want to spend an hour or so of utter stress and disbelief talking to a call centre half way across the world, speaking to some idiot who doesn't have a clue what you're saying, doesn't have a clue what he's on about either and has basically been shoved in front of a phone and given a flowchart of possible problems and solutions, most of which anyone with half a brain would already have tried (is the power cable plugged in? etc.)
customer "service" is a disgrace. I had severe problems when I connected with them this time last year, and their call-centre staff were some of the most unhelpful, untrained and generally clueless I have ever had the misfortune to come across.
A better idea is to get on the internet when you can, and search through internet message boards and forums as to what your problem might be, then try and narrow it down. Once you've identified it, it should mean you don't have to spend as long wasting money on the phone to some moron.
Better still, cancel them. Then, INSIST you get a BT
phoneline back and get an ADSL connection. We've just got Plusnet broadband and it's great - the customer service has been brilliant, and the connection has been just as good. And it only costs £14.99 a month.
On the subject of the connection, I found it to be absolutely great - when it worked. Which, to be fair, was most of the time.
Come fly with me, let's fly, let's fly away...