***** by MTN

I am being de*****ed by MTN.They say I have a contract for a Samsung S21 phone I have no knowledge of,my bank account is being debited on every last day of the month for an amount of R889 never authorised this on top of that I have never received any form of communication regarding this account.I called the customer care number 083 135 but no luck on getting assistance. I got a call from a number *** to say I am owing called it back does not exist.I am frustrated as this is not stopping please stop the debit I not in possession of a S21 phone account BA***