You can't charge me for a phone I don't have

On the 14th of September I was approved for an upgrade from MTN direct via a phone call from sales. I was told that it would take between 7 to 14 days to get my phone, but the insurance company would phone the day before to confirm delivery. About the 3rd of October I phone MTN to see what was happening with my phone as it had not arrived & no one had contacted me. I was told to phone the ********** 667 number. This was always engaged. Eventually later in the week I tweeted MTN as they did not respond to any of my emails or return any of my messages I tried to leave at other numbers. They tweeted MTN services to help, who asked for my details over twitter and then proceeded to tell me to phone ********** 667 (still busy every time I phone). I then phoned the courier company who were much more helpful, & told me they tried to get hold of me but I did not answer and MTN told them to send back the phone which they did on the 3rd of October - has no one heard of voice mail & leaving your details so I can phone back? I had no idea they had been trying to get hold of me as the 2 calls that had voice messages that I missed just had two women talking in the background and lots of noise around them. I finally managed to get through on the phone line, to be told I can only deal with the person who did the upgrade and he needs to send it back - I was then put on hold for 20 odd mins (total call before I hug up was 29minutes) Eventually I tweeted MTN again and they said the phone had been returned but knew nothing else. On Thur 5th October MTN then asked when would I like it delivered. I said Mon the 9th. There was no response so I left it to see what happened. Monday came and no phone. No one responded to the emails I sent, eventually I rep**** via twitter message & still no response. So I tweeted directly @MTN & was told that the matter was being re-escalated and that someone in the sales team would contact me (yeah right). So as expected no one has contacted me, I still have no phone and no idea of when it will arrive and no contact. I have told MTN that they cannot bill me at month end for a phone I don't have on twitter and email - this has just been ignored, and there is no response or confirmation.

I have been waiting 26 days for my phone, tomorrow is 27, almost a month. This is so frustrating when no one will answer any of your correspondence and no one can or will help and they just keep telling me the matter will be escalated and someone will contact me - which never happens. Does MTN even still have the phone? No one will answer this question (via twitter or email). Is this a legal issue? Because you really can't charge me for something you have not delivered and MTN has not upheld their end of the contract and I don't know if and when they will. What is the next step?