Appalling debit order system which does not work when you try to cancel your membership

Account system of debit orders does not work. It's impossible to ever cancel your membership. You will be charged by debit order for life. I cancelled my membership in March this year. For 3 months everything was ok but not for the last 2 months planet fitness has reinstated my debit order. This is theft. Please sort this out. I have sent e mails directly to planet fitness but apart from automated responses, no one ever gets back to you. Shambolic service. *** I'd ***