Cell C is a **** and I am never using their services ever again

Hi I had a contract with Cell C for the past 2years and last year I decided I won’t upgrade but rather cancel the contract and called them 3months prior to cancel the contract than they said I should wait 30 days and I did than than they said it’s cancelled together with my insurance but they still attempted to debit my account after my contract ended than sent my account to the lawyers for a cancelled ended contract now I am struggling to get anything done because of this inconvenience