Misold of the contract and bad service

Me and my boyfriend joined this gym and they have now re-branded to Fit24gyms the customer service is bad. I was told I was joining a fixed contact for 3 years but they increased my monthly charge and they said it because I am now a member for a year that why they have increased it. I let that pass bacuse it was not too much but the real problem is that they were debiting my account not on the agreed date and double charging me which is something I did not agree on. When I tried to speak to them and reason about this clearly I was misold. They told be that the is nothing thy can do , I have email the manager so many times but they are not resolving my complaint but still they are debiting I amnot even training and it been a while and I had no problem of paying but now they dont want to talk to me about my complaint becaue the manager is too buy to handle complaints.