Cancelling nightmare

I had a really good relationship with this gym for the duration of my membership but now that I want to cancel it is a nightmare. My contract came to an end in March and I am still paying on a monthly basis because that's just what they do. I didn't know until the end of my contract that if I don't cancel it will automatically start charging me as a cash member but I also blame myself for not seeing the writing on the contract with that said I have been trying to cancel my membership which was with the life centre branch but no luck in sight especially since they moved or closed down. I don't even know where to go or who to call since their number leads nowhere. I am tired of paying for gym that I am not using. Head office can't even seem to help me. I WANT TO CANCEL, PLEASE ALLOW ME TO! It is also frustrating that I cant do that with a single phone call. What can I do?