Unauthorized debit order deductions

I cancelled my contract with Vodacom effective 30 June 2021, on the 2nd of July a debit order went off - I questioned this and the lady said the debit order is for the month of June and not July, not sure if this is in fact the case. Again on the 2nd of August a debit order went off - I have no way of sorting out this issue as the Cancellations number (***) is for contracts and since I'm prepaid I can't use this avenue - also, the customer care line does not have the option to query accounts and the Vodacom store said I can only be helped via the Customer Care Line. I now have to carry the cost to reverse the debit order on my banking app.