Unauthorized Debit order and Not Refunding money

I cancelled my service with West Rand Reaction Unit due to moving house and confirmed prior to the end of the month that the service has been cancelled and that all fees is up to date, on the 1st of Sep a Debit Order went off, emailed the company and called them as well to confirm on the 2nd of September to be told that the Refund has been sent for processing. now on the 20th of September after numerous emails and phone calls I still have not received my refund and every time I call the Receptionist tells me the Finance Team and the Head of Finance is not in the office or in meetings and actually is astonished that they have not processed the Refund as promised. I did not reverse the Debit Order as I still believe in the good nature of people and to ensure they will stop the Debit Order run from being processed again the following month.