6 month delay in receiving refund

I had a trial at the westside location of Bodies in Motion, Los Angeles, in april 2007. I cancelled within the trial period, but the company continued to charge the monthly membership fee from my credit card. Despite numerous emails, and their promise to resolve the matter, it ended up taking until december before I finally received the refund on my card. At that point the amount of the initial deposit and the monthly fees already exceeded $500.