cheers for the replies guys
rang ntl again this morning, they said they're going to refund me the full amount (although they have to ring me back later today when they can get the full details on screen).
I demanded some sort of compensation for the aggrevation and that i would take the matter to trading standards, watchdog etc.. if they weren't forthcoming, and they said they will discuss some form of compensation when they ring back.
That's if they ring back...
This is the first problem i've had with ntl, and i've been with them for a while now, but it's totally put me off continuing with their service, although having read a few other posts, disconnecting the service seems like it could be a hassle too.