MTN charging for product not received.

I opted for an upgrade via their website on 16 July. Had to call to eventually get a delivery. after 2 weeks. included in package was a tablet, which I did not order. Had to send both items back. Since return, no word. I have called call centre numerous times. Answer " the phone is booked against my name, therefor nothing can be done unless this is sorted" Now, almost 2 weeks later, after various promises, nobody has called back. The upgrade is activated on my account, but still no phone. All I want is MTN to do their job...but it seems that is asking too much. If the phone is not tracked and delivered, will I have to log a case at SA police service, because MTN ca't find it?