Unauthorised debit

Telkom have been going back and forth to a Telkom branch for once stupid query and they seem not to able to resolve it. At the end of the June my debit order went off for my contract then followed by a R238 debit that i don’t know of, when I went to the branch they advise that i can reverse the money as they don’t know why i was debit that amount and i also got a call from call centre and they told me they don’t see any R238 debit from me besides my normal debit amount. I then reversed the money but i kept on getting sms that i must pay or my profile at the bureau will be affected, again today they took the money on my account and i can’t not accept this as i know i am not liable for this R238 going off my account.