MTN Treats Customers with Disdain

So a third party of MTN, Cell Network SME mis-sold the contract mobile phone to me by changing my monthly payments. Now I wanted to upgrade and take out a new phone MTN tells me I have already upgraded and I can only do so if I cancel the contract with Cell Network SME. MTN retention guys(Randal, Ana, Adefele) actually open an investigation with Cell Network SME and tell me the turnaround is 72 hours. After 72 Hours no one contacts me. I am given the number *** to call and no one picks up the phone. I go back to MTN retention guys they make me hold for a very long time and just cut the calls. I am told operations guys are dealing with the matter and the reference number is ***. Nothing comes of it. Why does MTN deal with Tele-marketing companies who don't care about customers. I am treated with such disdain by MTN as if I am not their customer at all. I have wasted so many hours trying to solve this issue, 72 hours have turned to 168 hours, MTN can listen to all my recorded calls to their retention department. Does anyone care about customers at MTN or we are just a useless number. Now I am just hoping.............!!!!