I kept getting calls from a number I didn’t recognise, I didn’t answer because it’s really iffy taking calls when driving, which is what I do for much of the day, but they never left a message I googled the number, seems it’s O2 Business. I’m on O2 but rarely get calls from them. Tried calling it, but got put on hold, so I blocked it. No more calls.
Orange, who I was with for a while, were the worst for dealers cold-calling touting deals for upgrades, even when I wasn’t due for one. I kept getting them for nearly two years after I went to O2, because I ported the number. The callers were very confused when I stopped them and said I’m not with Orange, I’m with O2.
Orange were clearly passing my number around their dealer network. Stopped now, thankfully.