Membership has expired but the debit order is still going ON

I subscribed for Planet Fitness Platinum Gym in Sandton in Radisson Blu Building. The service was fine but the staff was absolute non-sense and wouldn't understand basic stuff. The consultants show such attitude that its not worth a penny. After a year of membership, I decided to change to their competitor which Im enjoying as its really world class. Off late, I was going thru my bank statements and to my shock the ******s are still debiting my bank account despite sending a confirmatory email of cancelled membership. I have raised it with CPA & ombudsman for their attention. I don't recommend this gym to any client as its not worth the money.