Forced upgeade

I have been one of the most trustworthy Mtn client for over 10 years never missed a debit order. I wanted to upgrade one of my number which is due for upgrade I have 3 active lines with them. I was told that I need to send some documents the following day upgrade was done without required doc's and already I was on different package I was not happy I then decided I do not need this upgrade and emailed the lady THANDEKA MDLOVHU who had requested the docs. She did not reply to my mails and this now 3 weeks ago. When phoned his department I am told she is in and out of the office and she will not speak to me not even her sup or manager. Iam so ****ed cause my number is still on upgrade and I did not take new phone wait until they debit my account I will reverse the debit until mnt wake up if the blacklist me I will sue them