MTN - Be careful what you sign...

A year ago, on 2 May 2020 to be exact, I downgraded my contract from a very expensive R900 a month one, to R129 per month, at the Midlands Mall store. I was assured by the Sales Assistant that the very next debit order would be at the lower amount. Turned out that it was utter nonsense. I was told to "sign here, here and here", thereby unknowingly committing myself to a 24 month contract at R129 a month, while I STILL had to pay off 3 months remaining of the old contract, at the higher fee, lost all my accrued minutes and data in the process (while still paying at my old contract rates) and now I am unable to upgrade again, because instead of the month-to-month debit order I thought I was signing for, he had tied me into a 24 month deal! I have to ask myself: which company would prevent a client from spending MORE money with them?? Clearly, that's MTN...