Mtn
Upgrade with no phone?

I upgrade my contract to an iPhone 5 last week there was a factory fault on the phone now im paying R479 and no one can tell me when I'll receive a new phone as no one has stock. this is an inconvenience to me. My phone is used for work purpose! Mtn does not offer a loan phone or anything what am i supposed to do? MTN Oriental Plaza have been a great help trying to get it sorted but MTN on the whole the system you have is just not working