I want to have this ********** upgrade cancelled

This is my 3rd complaint to mtn...I requested that they contact me on *** about the upgrade that was **********ly processed on my *** number I have been calling the customer call and being told the query or request has not been attended, it's been a month now and mtn has failed to cancel the ********** upgrade on my number...I did send documents on the same day as they requested and was given ref number *** but nothing has been done and no one has even tried to call me, I was even told to call *** I was charge all my airtime but the number just rings, the next thing they will want to bill me for the for the ********** upgrade...I'm pregnant and cannot afford to pay anything more than for my one contract which is why I request to cancel the *** unnumber. I'm so disappointed! I will cancel my other as well cox I cannot work with such a service provider! Poor service!