Cancellation Nightmare

Hi I’m November I phoned to cancel my contract and to my surprise in December the debit still went through I phoned again in January to cancel the agent assisting me said the comment to cancel my contract was noted but it wasn’t put through so basically the contract was still not cancelled I asked him so who must pay for January he aid he will let me know he will phone me back he did call back and said a lot of things and I asked him to listen to my recording cancelling the contract he became rude now I just check my bank statement Cell C debited me 3 x months after I have cancelled the contract is that fair for been a good customer and as someone who phoned to cancelled and your agent made a mistake . Must I pay for mistake made by your agents?