Being inconvenienced for a mistake at the branch

I've been with MTN for more than 12 years. I app**** for a tablet on contract for my son and received it on 2 July. I requested the account to be a top up and to have a R1 limit for data as the 1GB of the contract should be enough for him. On 30 August I phoned 808 to confirm that my debit order will go off on the 31st. I was told that the limit was NEVER set and that my account for data was almost R2000, which later changed to almost R3000, only for July. Up to 30 August the new month's amount was R700. I went to the branch on the 4th and asked them to log a call, which was never done. The next Thursday I went there again, after not receiving my promised call by Tuesday, only to find out the call was NEVER logged. Again, promises not kept!! Kagiso assisted me and did log a call, but when I went there again today as I have not heard ANYTHING, NO FEEDBACK AT ALL, I was told it could take up to 60 days and that my account will be suspended if not paid in full. THIS WAS NOT MY MISTAKE. IF THEY DID THEIR JOB IN THE FIRST PLACE I WOULD NOT HAVE HAD THIS ACCOUNT. I AM DISGUSTED WITH THE SERVICE I'VE BEEN GETTING AND WILL MOVE MY ACCOUNT ONCE ( IF EVER) THIS IS RESOLVED.