Although I'm sure it does not ONLY involve TalkTalk customers I can assure you as a TT customer I get between 1 and 3 calls per day at least from these Indian call centres saying they are form TT, and banning the numbers is futile as they spoof the caller ID. The difference now is that when you politely ask them to stop calling you get a tirade of four letter abuse and even from the women calling not just the men. This is getting both ridiculous and serious, if one of these guys were answered by my wife she would be very upset to get such abuse for no good reason.
I have been trying to get TT to restrict all calls to my home phone from overseas but they are not responding. Next is to complain to the CEO - AGAIN, and then to OFCOM. There is no reason TT customers should have to put up with this. TOTALLY UNACCEPTABLE.