Gym Company review: Membership

I took a membership end of October for beginning of November 2019, my first debit was on the 20th November. to my surprise I get double debited on the 20th February, I reversed it because I've never missed a payment. when I get to gym I was denied access, bathi I owe levy fee. Now on my contract I was told levy is payable in november for a whole year, so I took it since i started in November, I'd start paying levy after a year of my membership, it is for a year afterall. Nobody told me about the February levy. I took their managers email address since he starts work at 9 and I go there at 6am, I emailed him my concern yesterday, he did not respond. This morning I went to gym, I was denied access, I was told to pay atleast R50 to go in. i feel bullied and really taken for a ride here, is this allowed? this gym can just decide to randomly double debit you on any gven month? if you do not allow it, you dont get access. Even if that levy was due, do I not qualify for a pro rata amount seing as I only started gym in november, so I pay a full amount of levy for just 2months? please assist, we can not be treated like this as customers. Thank you.