Unauthorized debit order

I've had enough with multichoice. My pricelock ended and I clearly explained that debit order is to be cancelled, this went well till they invited themselves into my account again in October and November. I contacted them to enquire who gave them this authorization as it was not me and the ****en agent couldn't explain. She said she will escalate this matter and an agent will contact me . Not even one agent has called me and I want my monies and explanation on who said go into my account because that's *****, ******** acts and ********... I want my money back ..here's Ur stupid ref ***