I DON'T OWE MTN ANYTHING

My contract number ********** . I called MTN the 30th October 2017 to cancel this contract. They notified me I can only cancel 1st November 2017 and the contract end date is the 24 November, which means it will automatically go over to top-up 6th November I called to Cancel. they informed me contract is cancelled Now I was billed for December and January when this should have been cancelled. I dont owe MTN anything infact MTN owes me. I dont want to sit for hours on the phone to sort this out cause they put you through from one line to the next