recieved a message on answering machine that my ip address had to be changed, no reason given but to press 1 to continue. Needless to say i did not do this as i thought i would be contacted by BT if such a thing was required. I also didn't trust the fact that it was a person with an american accent, and the number wasn't a recognised uk code, lots of scammers around!!!
It is obviously a scam. If there was ever a need to change your IP address BT would not need to contact you, they would just do it and you would be none the wiser. The only exception to this would be if you were a business account user and had a fixed IP address.