GYM Company is Evil

I cancelled my membership at the end of my contract in May 2019. Up to now, Jan 2020 they're still debiting my account, despite numerous phone calls & emails telling them that I have cancelled my contract. I have reversed the debit order, but they keep debiting the following month. This is impacting my Credit score, as it comes up as a "dispute". Now I must suffer in the hands of irresponsible entities & executives/owners who don't take their fiduciary duty of care seriously.