Maybe it's a coincidence, but it has happened in the past, that I start to receive many scam calls purportedly from Talktalk, after I have been in touch with Talktalk mobile. I have had 3 or 4 per day warning me about my internet connection etc. Only 1 call had a "live" woman, speaking with a heavy accent, at the other end and she put the phone down when I laughed at her. I am now using TT's blocking tool after each call-when I remember it. The numbers are all different, probably because they are using a random number generator, and some are a digit short for a uk number. As far as I know they are all fake, but I am not going to ring them to find out, as that could be another scam. My faith in Talktalk's ability to deal with these is diminishing rapidly.
You could also try activating CallSafe , which has been proven to deter scam calls and allows you to block any number, You can read about it on our help page About CallSafe