MTN continues to bill for contract that is suppose to be cancelled

I called MTN to cancel my data only contract. I was informed that the contract end date is 17th November. I made a call in October to request the contract to end upon the end date and they advised that a note will be added on the system and November would be my last bill date. My contract amount is R299 per month. And I was billed over R2000 for November. I have not received a bill for this amount. And get no response from customer care or cancellations.