MTN won't let me cancel my contract

I have been trying to cancel my contract with them for months. In August a consultant said that if I pay a certain amount they can cancel it, after numerous calls, they then tell me that sorry I can only cancel in October. Phoned them early this month after payment has been made for my 24th month, asked them to please cancel, no sorry, you have to phone us back on the 25th. Phoned them this morning, no sorry invoice date was the 15th, I have to pay for November before they can cancel. This is absurd. I will not pay for next month when I am on my end of my contract and I want to cancel it. I will never get a MTN contract ever again. Worst cellphone provider EVER!!!!