charged for a cancelled contract,

i had a contract with cell c which is canceled 07/10/2023, but now i keep on seeing them debit money out of my account and i phoned them more than 20 times but no one is willing to help and Saturday i went to the manlyn branch and they were not even willing to help me and i do have the confirmation of the cancelation. CELL C why did someone in your company decide to reactive the contract? look at your records and fix this and remove me from your list and stop charging me for contract i have cancelled