Bad service from the gym

I joined a gym at Maponya mall in December 2011 it was a promotion special that you join in December and start paying your first installment from month end of February but I called the promoter within 30 day to cancel and he told me that I cant cancel once I have joined there was nothing he could do therefore I never attended the gym and I never paid so now i m listed and I have never received a call from them or any letter of demand but now I'm listed.