Unauthorized debit order by platness fitness

I was once a member for planet fitness which later on I canceled due to the challenges that were experienced by my partner unable to access the fitness Centre in my absence. He join for himself, they then debit from his account. I then experienced challenges of debit order from my account which was not authorized and when I enquire with them they gave me a run around and they end up closing the matter without resolving the query logged. Till to date I have not recieved any response from them neither reimbur*****t as per their promise. The ref number for my case is as follows: PF***