No Contract but liable for 24 months!!!

I phoned Planet Fitness thinking my contract will be up soon, just to find out I am loaded on a 24 month membership and not a 12 month membership, I handed in my Multiply membership details, meaning I should of been put on a 12 month membership in March 2020, then lockdown happened and all gyms were closed, meaning I never got to actually sign a contract, since March 2020 till now Feb 2021 I have been a maximum of probably 5 times as I am working from home now. Now they say I don't have a contract but because I was loaded on the system for 24 months I'm loaded till July 2022, but they are going to try find out all information. How can I be kept to 24 months without even having a contract, when I can't even attend the gym.