I have a Virgin phone, used TPS, I block withheld numbers, and it doesn't stop the calls - we get more than one a day.
I'm seriously thinking of investing in one of these...
https://www.truecall.co.uk/home.aspx
£100 seems a lot, but I would hope that in my configuration all I need to do is to handle international numbers a bit better and I hope that I'll be fixed. Does anyone have any experience of TrueCall?