Debit order misuse

I had a contract with Telkom that ended 11 March 2021. I went to customer care at the end of Febr. to verify this. I was assured by the agent that services would be terminated by that date and the debitorder would be cancelled automatically but i should also cancel it with my bank,which i did.I left for Canada on 2 March. A reduced payment went off end of March and again in April. I had to reverse the payment. Capitec is not willing to help me,saying they are obliged to honour the debit order.End of June the took R801 and R1200. They know if they change the debitorder amount,it would go through. I know i am not alone and that a lot of people experience the same theft from Telkom . How do we end this. I am still in Canada and unable to sort this out in person.