MTN misleading customers

On the 14th November i called in to cancel my contract as i received a sms that i would be charged R1500 as it will go month to month so i called customer care and they transferred me to retention's which they advised me that i can upgrade and keep the same deal i agreed and upgraded i also asked the consultant if i would still be paying the R1500 at the end of the month if i upgrade the consultant told me no i wont il just be paying R318, on the 30th November MTN debited R1818 which made me furious. I called retention's on the 1st December and spoke to Annalisa and told her my story she says she cant help me and the consultant who did my deal will give me a call before 3pm and sort this out but i did not get a call, My problem is that why mislead me into upgrading and tell me i wont be charged where as i could have not upgraded and i clearly will not be paying R1818. MTN needs to change their consultants and especially how they do business. contracts should end immediately and not go on month to month charging customers crazy amount there after that, I am very disappointed with MTN and i have been with MTN for the past 15 years