CellC - Account that is on arrears for no reason

I terminated my contract with Cellc on the 30.12.2021 due to poor service they were giving me and i made the termination payment via my capitec app, they gave me Nedbank account number to pay cancellation fee of R1309.00 so that they can close an account and again on the 31.12.2021 they deducted amount of R567.98 i don't even know what was for. then, now two years later I am receiving calls and emails from wefinance properties Attorneys credit bureau telling me my name is on arrears with Cell C account. I real don't understand how does this thing of cell c works serious. I am so fustrated. This thing it's affecting my credit score, mind you i have properties and car that i am paying. The day i paid their R1309.00 they charged me i did sent proof of payment to cancellation department and customer service email address, but still they are putting my name on arrears. Please i need help