Cancelation of contract

I'm not happy with vodacom. I've been trying to cancel my contract with them since July 2020 i sent them email asking about the end date of my contract and they reply and tell me that my contract end date is on the 03 September 2020 and i need to call a month before the end date to notify them about the cancelation of my contract and i did that but to my surprise vodacom still debiting in my account please help i don't want anything that has to do with vodacom anymore