Contract cancelled and still debitng my account

Wifi was cancelled on the 18 August. My account was still debited I called again and was assured on the 1 September it was cancelled and would no longer be debited. You still continue to debit my account. I called the call centre and was told that you are not able to cancel your account via phone call. When I was previously assured on two occasions that the contract was cancelled. My bank has been notified that you are NO longer allowed to debit my account. I have sent numerous emails and received no response. Call centre staff need to be trained better as one doesn't know what the other is doing.