0800 996 1966 and 01 800 996 1996
I have a TrueCall unit - bear with me - so marketing calls don't get to ring my phone. I also block international numbers but overseas friends can get through by using a code. I have an old Caller Display 2000 unit between my wall socket and the TrueCall unit so I can see for my own amusement how many marketing calls have failed to get through (otherwise I'd never know). I've set TrueCall up so they - and international callers - hear the number unobtainable tone.
Recently I have been getting a number calling which shows as international but has the number as 0800 996 1966. According to one of the 'whoiscalling' websites it's a Consumer Lifestyle Company doing market research. With them having got the unobtainable tone on 7 occasions over two days they switched their CLI number to 01 800 996 1966 - possibly they thought I was blocking 0800 calls but wasn't blocking 01 numbers. I don't block 01 numbers but it was still an international call so it didn't get through. Just shows what they do to try and get through.