I regret taking a contract with MTN

I have been trying to cancel my contract for 3 months now.. I called to cancel back in November and they said that it has been processed, only to be billed 4times the contract amount in December.

I called again in December to confirm cancelation, they keep saying I need to speak to the cancelation department, but the cancelation department does not answer my calls I keep listening to their music for hours without getting any help.

We are now in January and I still can't get through to the cancelation department and they have billed my account again.