This number seems to be from London, where the scammers cold-call people in the UK pretending to be Carphone Warehouse. Carphone Warehouse does not cold-call customers. For the past week or so, they have called at least once per day and first began calling back in mid-September. Some of the numbers they have called me with are listed below:
020 8058 6867
020 8058 1989
020 8105 3800
0151 700 8711
020 3239 3985
020 0881 8315
0161 850 3227