Mtn full of empty promises

Very bad service. I have 6 contracts with Mtn and still they can't care any less. I was doubting on renewing one of my contracts and a lady named Thando from retentions convinced me to upgrade because she could offer me the device I was interested in. My application was submitted and approved. I was promised she would call me a few days later as the device was not in stock until the next week, it's over 3 weeks now and she hasn't got back to me. I told her it was urgent. Nobody could help me further. I've called over 20 times and sent many emails to her via her colleagues yet i got pushed from pillar to post. Seems lime nobody really knows how to assist a customer. I will seriously consider whether I'll be doing business with them in future. I even asked to escalate the issue to a supervisor who was busy at the time, the agent promised me the supervisor will call me back. I called Mtn online for new sales and after waiting for 20 min on the fon, they also said they would call me back and guess what? U right, nobody did!!!!!