Solution - I have carried out research in regard to nuisance calls over the past 18 months and the results have been as follows. TPS & OFCOM as good as they are do not have control over companies from overseas masking themselves as UK callers when shown on caller display.


TRY THE FOLLOWING IT WORKED FOR ME

ANSWER EVERY CALL
DO NOT PICK UP THE RECEIVER
PLACE THE CALL ON HANDS FREE UNTIL YOU HAVE IDENTIFIED THE CALLER
IF IT IS A COLD CALL OR SALES CALL JUST IGNORE IT
LEAVE ON HANDS  FREE UNTIL THE CALLER TERMINATES THE CALL
REPLACE THE HAND SET

You will receive a number of calls but because you are controlling them it will be satisfying and the calls will stop

I have been using this method for over 18 months now and it has worked for me

I have also reported callers and companies to OFCOM and although they do warn companies of the consequences in regard to silent and cold calls in regard to prosecution MY 6 point plan has been the most effective for me.
In addition use variable incoming caller ring tones this will enable calls to be identified prior to answering them