Yello no phone

I upgraded my contract in the beginning of January to an iPhone 6. Two weeks into having the handset it started \blue screening"an continuously rebooting on me. I returned the phone to the store I had purchased it from who subsequentely sent it into the MTN repairs department. The return was on 22 January 2015. The returns department is supposed to have a 24 hour turnaround time. The phone was only receipted into this department on 27 January. I have now been told that there is a backlog and that there is now a 14 day waiting period. I am without my phone and can't get an anwer out of MTN. No replacement has been offered and basically it is just bad luck that I am inconvenienced. I have been an MTN customer for close on 20 years now so would think that surely there would be some concerted effort in terms of customer service"""