Contract cancelled - Poor service

I joined the Gym Company in April (month to month) I cancelled my contract in October (3 month notice) In November i get debited twice, the same amount and its a maintenance fee When queried via email, The GM from Alberton rep**** saying its a maintenance fee. I rep**** asking her name and no response I went to the branch and of course the GM Thandi Mkhize could not be bothered to help the situation. month to month contract for 6 months, contract cancelled and they still debit you cause you on the system, daylight ******* December should be the last debit order. Am i to notify my bank to stop future debit orders as reading all the reviews, you keep debiting people