Imei ***

I complained about MTN already and still nothing happened. I'm still without my Apple Iphone. We send the phone in for repairs. Imei nr ***. MTN said they tried to phone me but the only call I did't recognise was a PRIVATE call. MTN did't leave a telephone number I can call back to they also did't leave any message. MTN want the Imei nr of the phone but to whom must I gave the number??? I am struggling nearly 8 months now to get a Iphone screen fixed and this is really rediculous and I am fed up with MTN and their service. job card nRETZA ***.