Contract Renewal - Extremely poor service.

On the 17th of December 2021 I was called by one of the MTN accredited dealers and offered an upgrade deal on my 2 cell numbers, to which I agreed on ........446. I received email confirmation of this on the same day from the dealer (dealer code: SABC1722) Since this nothing has been finalised and I have been harassed by numerous other dealers wanting to upgrade my contract daily. What is worse is, that even though I have made numerous calls to MTN to get the problem resolved, nothing has been done. More annoyingly is the fact that I am still getting billed the old rate which is nearly double the agreed upgrade rate. Can someone please assist with resolution?