Been called 8 times in one week answered once phone was put down, checked with ICTIS (Not Registered) OFCOM (says register with TPS) Already done this last year but re-done it again this morning.
Googling different parts of the number ie 0161 343 8778 shows pages and pages of businesses from taxi firms to interior desiner all located in the Manchester/Ashton under Lyne
It seems who ever they are, they have hidden themselves in a sea of popular telephone numbers either 0161 343 or 343 8778.
If they keep ringing, fill in a complaint form for the TPS if registered.
If after 8days (regerstered) 28days (un-registered) you are still getting this number, make a complaint to OFCOM.