The TPS is a product from the Chocolate fireguard Company
All they do is cut down the calls that come from within the UK, and not all of them. However, any time-waster that is is dumb enough to use a UK number gets reported. I use the “whocallsme” service to see if the number is a known telepest, and see what they normally claim to be calling about, first.
Try to make a complaint and see how many types of call they do not deal with. They will refer you to the ICO - which is another waste of space - for a wide range of calls.
If you are waiting for a call from a hospital or from a GP Surgery, they will both show up as “Caller withheld their number” (translates as “came through a private exchange”) so you answer it anyway.
BT could stop some of the calls stone dead - the ones that have spoofed the calling number - but they do not want to for some reason. If you knew that the calling number was presented as 0000-0000-0000 would you answer it? But BT let it come through.
Last week it was a string of calls about my accident (or “someone at your address has had an accident”), today it was two calls about the virus on my computer. When I cannot ignore a ringing phone, and it is a time-waster, I fall back on the hash key (#). Just tap it rhythmically about five times and then hold it down. This creates a tone that could be a system fault - so the caller hangs up. So you hang up and you have a clear line