Worst decision - Cancel my contract

I joined zone fitness about 1 month back due to proximity to where I live-it's convenient for me.it took me a while to sign up as I wanted to make sure the gym itself would work for me.I signed a 2 year contract with them which has turned out to be an utter dissapointment. The sound system for daily classes has been faulty since I started-which has been addressed with management by various instructors and clients, gym equipment is dated and not well maintained, classes are often cancelled-so when you plan to do a step class for eg you will arrive being told it was cancelled???I'm not happy with this gym facility at all-contractually I'm not getting what I signed up for. Also, the main reason for me choosing this gym was the greenlight policy discount-when i enquired about my gym attendance to submit to Old Mutual i was simply told they not affiliated with it any longer? Which i know not to be the case...Please cancel my contract with immediate effect.