MTN FAILING TO DELIVER!!! THEY ARE *******

My phone has issues and I reported this matter to MTN in December 2015. I filled in a handset insurance claim form at MTN Pavillion branch on the 23/12/2015, as I pay monthly insurance (MTN Limited Equipment Insurance) for my phone. The MTN insurance company called to inform that they would be collecting the phone after two days to take it in for repairs - unfortunately that never happened. I have been waiting since December and have attempted a number of times to follow up but have had no luck. It is now almost 3 months since the matter was first reported and my matter has not been resolved. The reference number that I was given in December is REQ***. I called again on Friday (11/03/15), I was referred to MTN logistics department where they gave me the reference number ***,206895 and ensured me that the phone would be collected on Monday (14/03/16), which again they failed to do. I pay for insurance every month, which is clearly a waste of money!!!!! I demand that MTN give me a new phone because I am tired of the empty promises and apologies - MTN has let me down countless time.