MTN Poor service

I was advised on the 3rd of Feb that my contract had expired and that the subscription would increase from R199 to R1217 per month, I immediately called MTN customer service and requested that the number be cancelled with immediate effect. I then received an sms to say that the number was changed to a MyMTN Zero price plan and the other plan had been removed. I then received my bill on the 17th of Feb which reflected an amount of R1080.00 as well as a migration fee of R100, this was shocking to me as in mind everything had been resolved on the 3rd. Despite numerous calls to MTN and being shoved from one person to another I have not been able to resolve this matter and it seems that I am expected to pay the price for MTN's incompetence despite advising them that the simple way to resolve this is to check the recording of the initial call that they love to tell you about. I am utterly disgusted with the service that I have received and it is a huge concern when you cannot speak to a manager or accounts department when you have a query nor can anybody at the stores help you with anything. In my opinion it seems that MTN does as they please and the customer pays the price whether you agree or not.