Unauthorized debit order

Gym company is an excuse of a company, its entire establishment is a *****! I canceled my contract 8 months ago, after 2 months they debited my account again. I addressed the matter, went as far as going to their offices with the paper work. Their response to the mess they had caused was that I should just reverse the debit order, a reversal that I had to pay for and in turn it messed up my bank statement. This all happened in 2019, now over 5 months down the line they are debiting my account again without reason. A few days ago one of their agents named Gary (if my memory serves me well), he phoned to tell me about some app. I told the guy that I had canceled my contract with them and that I wasn't interested in anything that he had to offer. A few days later, that's when they debited my account. I even have a recording of the phone call. Gym company has always had poor service, especially their Randburg branch. It seems they are using the impact of the lockdown to rob people in order to keep their nonsense of a gym operating. I'm at a point where I'm prepared to take legal measures, if ever I'm expected to send through paper work again, the only place I'll be submitting the documents is in court!