Awaiting Delivery of a cellphone

I recentlty took my phone back to MTN as it was faulty and they finally agreed to replace the phone. Now the problem is that I'm being told that Thandeka will arrange for the delivery of the phone and she will contact me. I have not heard anything back from her, I keep sending her emails and she keeps ignoring me. I'm sick and tired of this pathetic service that I keep getting from MTN. It's now almost a month that I've bought this cellphone and I'm unable to use it. I want my phone to delivered ASAP. You call the call center and no one gets back to you. Right now I'm paying for a phone that I don't even have. I've sent an e-mail to their complains dep and it's now more than a week and still no response. Clearly MTN does not value their customers