Unfair treatment

I was approached by the sales people to join the maponya gym. This occurred last year 2014 December. They took my details and said if I want to join gym I can come this year January for free and they will charge me from February if I join and actually go to the gym. I decided that I'm not going to go only to realise that they gave me wrong information that I'm agreeing to a 3 year contract and being part of the membership. I only became aware of this as my bank account was debited last month in February. I am currently a student and I'm not working. So I tried talking to the people in the offices but all they tell me is they can't do anything. My issue with them is that none of this was said when I was told about the gym and I wouldn't have agreed to this knowing that I have no salary or income to join the gym..