Cancelled my service but money is still being deducted from my account

I cancelled my service that I have not been using on the 25th of September. I had to go back and follow up with my reference number that they could not even pick up. After going back to the store speaking to numerous agents I still haven’t had any feedback on weather or not my account has been cancelled. The last agent I spoke to said that he logged in another request!!! Still no one has phoned me or stopped the service you are deliberately taking money from my account after I have requested it to be cancelled! What poor customer service