Problem with upgrade.

Dear MTN Customer Complaints Office and Upgrades. I have been struggling for 4 years with my contract that you have made a mistake on, and now I cannot upgrade to a new one. One of my contracts has already expired and if this is the case, I will be forced to change to another network provider because at this moment my phone is not working properly and this is unacceptable. You are always willing to sell us everything but never seem to help when there is a problem.