A warning...
I used to be a BT Broadband customer, but changed to Sky in February.
BT withdrew the service with the cutover and that was that.
But I've just checked my credit card statements, and they've billed me for the service again for the past two months!

The moral of course is don't sign up for things using credit cards or any system that lets the vendor decide how much it's going to take from you.

Pay for things by automatic payments where you stay in control or best of all, by cheque ideally as late as possible.

I can second that. I work for a large bank, if you need to stop an automatic payment last minute you are basically screwed. Many banks offer online billpay services that can be free to use, and give you total control of the payments being made.

~P~