Poor customer service

I have endured 24 months of inflated invoices on my MTN contract. The contract expired on 9th December and I requested that it be changed to prepaid. Instead of that being addressed, instead Katlego asked me why I wanted to change because I'm eligible for an upgrade. I explained that I do not want to get an upgrade because of the inconsistencies with their billing and that I would rather upload the airtime myself so that I can control what I spend. 2 weeks later I'm being told that my request will only be attend to after 1st January 2016. Surely this is *******, I can't be kept on a contract that has lapsed against my will. Infact I would advise anyone who wants a contract to think twice before they are ********** by MTN. Reference Number: ***8