Best bet is to go ex-directory and register with TPS and eventually the calls will diminish.
With the greatest respect this is bunkum.
With the greatest respect also, no its not Bunkum. Its worked for me.
In the end I ended up buying a programmable intercept (Trucall) and after a longish time programming the thing, my nuisance calls are down to about 3 each day.
I don't have any sort of call blocker, and on average get LESS than 1 call a week, quite a lot of which are 'Silent Calls' probably computer generated. The occasional 'You've had an accident' call from India is answered with stupid replies and they soon give up.