UnAuthorized debit order

Vodacom services is extremely appalling, my frustration with Vodacom is that my contract with them has expired on the 27th April 2020 was advised to call a month before to indicate that am not renewing it, but after that from the month of May 2020, they keep on debiting R60.00 from my bank account and i have tried to call them so many time without a success and the call center is useless you can never go through and if you manage to get through to cancellation department(***) is either the agent ask you to hold and eventually drops the phone and forward your call to survey section. I have also tried to engage them on Twitter but they tell me that nothing they can do, i have to keep on calling. I also send the email to cancellation department but nothing is done. The number linked to debit order is ***. But you can contact me on ***. Can i have this cancelled..Regards William