Crunch Fitness review: refund

In October I agreed to a personal trainer. I was told that I had to pay 4 sessions up front, which I did on my credit card.
My personal trainer quit in October but worse than that, my credit card was being charged 135$ every 2 weeks. Crunch owes me in excess of 600$!
I have visited, called, emailed and have not received my refund. I saw the manager once and he promised I'd get a refund.
Most emails go unanswered and I am at my wit's end.
I want my refund that I've been waiting 6 months for.