Charged for one month erroneously.

I was charged for one extra month on my landline contract. I called the call center 1 month before contact can expire to cancell the contract at expiration date. I was assured that the contract would be cancelled. I called the call center numerous times thereafter, the agent even confirmed that an instruction to cancel the contract was given by me. This negative information has now appeared on my credit report and is jeopardizing my chances of getting my mortgage bond approved. I have proof that it was the information supp**** by Telkom that has negatively affected my credit profile.<br> I would like this matter to be resolved as a matter of extreme urgency, and that the information supp**** to Transunion be retracted.