Unreasonable Unfair Demanding Of Payments *s#@%?'

I received an email informing me that my name has been handed to VVM attorneys for collections for outstanding debt. I recall very well that I had a one year contract with the gym and a month before my contracted ended I personally contacted the gym to cancel any further debits from my account and it was confirmed on the call that my contract shall cease. That was in early January 2017. After that I was contacted by their sales pursuing me to renew but I was not interested due to their ridiculously high fees and lack of professionalism. Today 2 and half years I received this irritating email that I owe them R529. I am so disgusted that I took an initiative to cancel the contract but they still got a nerve to bully me and demand something I do not owe them.