Refuse to close a account after payments are made

Went in to mall of Africa , sept 2023. Asked them to close the account for data, I paid upfront, paid the whole account in full and the remains at once. Staff said , printer not working , they will email me they closed the account for data. still not reply or anything. 6 months later VVM calls me and says I owe R500. Really pathetic and theft. Reported to Vodacom. Apologies were made they will sort it out. Still VVM call and irritate me. Not my problem Vodacoms staff cant do their jobs. Now I must pay money which I asked to settle and they just keep billing R100 every month. really bad that why I moved to MTN