Breach of contract with rewardco

Breach of contract. Incorrect amount debited not agreed upon on contract. I have an MTN contract through rewardco. In December 2026 an incorrect amount was debited from my account which is not in the contract i agreed upon. I contacted rewardco and they were going to investigate and still have not come back to me a month later. I received a new invoice for January 2026 and the amount is not as per agrreed amount. This is a breach of cobtract and *****ing from my bank account. If i stop the debit order i wi be blacklisted and i do not want that. I just need MTN to rectify as theyre the ones taking my money. The case reference for that call Case number rco751117 and spoke to Yonwaba mvula who wouldve escalated and investigated. But havr not heard back.