Incorrect billing

I contract expired in October 2017 with Planet Fitness then it has been month to month contract until one day in February 2018 I went to the gym & I was declined entry as they have advised that they never received payment. From February 2018 I have never used the gym again but every month until June I have been debited. I cancelled the month to month contract with Planet Fitness in February but they continue debiting my bank account. I have reversed those debit orders and my bank has charged me for all those reversal.

Now I am receiving calls from their collection company that I owe Planet Fitness & they are taking legal action against me.

I have requested Planet Fitness several times to assist me but they did not I want to know from Planet Fitness, What are your customers paying for monthly? Are they not paying for the gym equipments that they use. I have not used their equipments from February 2018 but they keep on charging me.

What exactly I am being charged for????????????