Non-activation of Services

I’ve been calling MTN for the past week over at least 15 calls and in each case they haven’t been able to assist me. After I did a sim swap my iMessages and FaceTime services have stopped working. It is known that the service is activated through the service provider being MTN in this case. I bought multiple SIM cards from Vodacom, Telekom and MTN. On all these SIM cards including a new MTN number iMessages and FaceTime work perfectly fine. The issue is with my number which they should be helping with. All attempts have been unsuccessful and no seems to be willing to help. I keep getting transferred from one team to another and promises are made to call me back but to date no one has.