I had this same issue, I was getting calls after calls from people saying that I called them when I hadnt called them. To make matters worse the O2 technical support i was on the phone with, barred my phone number and that ended up rendering me out of service. I have no idea why he would do that without my consent.
Anyway when that happened, I drove to an O2 shop and they were not helpful. The staff at the shop made an excuse that his system was a new system and my data was not available which sounded like bs. I must say am really disappointed with the O2 customer service in middleton, manchester they did not help to unbar my network and bring me back the network signal.
I just reactivated the e-sim about 24 hours later and the number of unknown callers have reduced. I still get the odd calls here and there.
Just researching this seems like a known issue called spoofing. O2 should have a way to resolve this issue. it is a very uncomfortable feeling and they should train o2 tech support, on how to solve the problem or advise their customers accordingly especially for customers who dont want to change their number. what would have been idle is to purge the log queue of incoming calls.
