Annoyed Client - No sense of wnating to assist

I am a very irate customer at the moment. In November 2018 I received a call from Summer mobile advising that my contract was due for an upgrade. I specifically advised that I didn’t want to upgrade as I was awaiting new devices to be released. I have now decided to upgrade, when trying to upgrade I have been advised that summer mobile has done a sim upgrade on my contract without my knowledge. When contacting them on Monday I was advised it will take between 3 to 5 working days. The call centre agent I spoke to there is very rude…. I called again today and have been told that it will take between 5 and 7 days, there has been no response from MTN. When asking the agent to go back on recordings to listen to the feedback provided by the agents regarding turnaround times I get no luck. I want this transaction reverse as a matter of urgency.