Contract Cancellations not processed after multiple cancellation attempts and still being charged!!!

I "had" a Cell C data contract.

I knew I did not want to renew the contract so I phoned Cell C in advance to cancel the contract. I knew I would have to pay the contract till the termination date but that was not a problem.

The month when the contract was to be cancelled I receive my invoice only to find the contract is not cancelled, has been automatically renewed and I have been charged.

This was after multiple Cell C employees phoned me to renew the contract and I told them all I have cancelled the contract I don't want it renewed.

So I phone Cell C again, after multiple operators and fights they confirm the contract is now cancelled and I will receive a refund for the 25th months' incorrect charge.

Today I received my August Invoice and the refund was not processed nor the contract cancelled and I am still being charged for it.

So explain to me how Cell C automatically renewed my contract in contravention of the CPA.

Or how CEll C completely misinterprets Sec14 of CPA, my notice was in excess of the minimum 20 days notice and I agreed that it is not an early termination but rather notice of cancellation and non-renewal.

Now how long until this contract is cancelled and money *******ly charged refunded?