17 months after cancellation, I still owe GYM Co??

17 months after terminating my membership (at the end of my contract), I just received a WhatsAPP message from them reading as follows: "Your gym membership is overdue and in arrears. We offer amnesty cancellation of R1000. ...". How crazy can you get a still run a business? I spend 2 months fighting with them about them cancellation. They were still debiting my account because the termination had not been processed on time, even after a visit to the gym and numerous phone calls. Where can I report such a company for ************ business conduct? Which ombudsman handles this industry? This is totally unacceptable