Bad service

I was called by MTN to do an upgrade of my contract in november, I had difficulties in geting the hand set and then by the time they called i then told the agent that wanted to cancel the upgrade and i will go to the store and do an upgrade by my self when ever i get time. The call center agent agreed and told me that the contract have been cancelled, only to find that the contract was never cancelled and that the invoice came with the amount that i was even not awere of. I had to pay for the service that i did not get. I then on went to the MTN store in Nelspruit to complain about the matter on the 30 november 2017 only to find out that my upgrade was never cancelled, the lady who was helping me logged a call . Even today i have never got a responce, I have even called the CCISA costomer centre and the call centre agent told me that they cannot help me. I am really frastrated as to i will be paying for a service that i do not have again as the month is ending soon and i feel like MTN is not taking my issue seriously. I AM REALLY NOT HAPPY WITH THE KIND OF SERVICE I GOT FROM MTN PLEASE MTN CANCEL MY UPGRADE I AM NO LONGER INTERESTED IN YOUR SERVICES.