Unresolved continuous debit orders

Hello Peter. After cancelling my policy before it could even become effective, Oaksure debited an amount of R750 on the 1st of June 2018. I reversed the amount as per agreed over their recorded phone calls for security reasons however, Oaksure continuously debited R750 from my account every Friday since the month of June began. I asked for confirmation to assure me that they wont debit from my account anymore however I was told that their phone calls are enough assurance since they are recorded. They keep debiting this amount while their system shows that my policy was cancelled.