This number also phone me the cellnumber which I know nobody knows. I think they are scammers.

also got various calls from them (apparently Old Mutual) asking for my ID, I asked to verify themselves, but they quickly hang up... no answer on call backs

I called back number 021 533 0540 rang once then gets disconnected automatically.

number stays busy

Called me repeatedly while I was in a meeting. Whenever I got a break and try to return the call the number is busy.

old mutilual

I called the number back and I can only hear the background. It seems like the person is just listening.