Being billed for my upgrade but no phone received!

Good day, I went to MTN Atterbury to upgrade. I decided on the Z3 Compact. This was two weeks ago, and I am still waiting for my phone. When I call the store no one answers, and when I spoke to them a week ago they told me there's no stock. Really, after two weeks still no phone!!! I am thinking about changing back to Vodacom (I ported to MTN a couple of years back)! When I call the customer service and press 0 to be transferred to a consultant the phone goes dead, what is going on!!!!!! If I do not get my phone I will change to Vodacom or Cell C.