Bait and Switch!

I signed up for 8 personal training sessions that I paid for in advance.  YouFit started trying to charge me monthly for more personal training sessions, claiming that I had signed a contract which said I agreed to 4 Months of sessions.  When I was signing up it was made clear that I was signing up for 8 sessions and AT NO TIME did anyone mention the recurring payments.  I cancelled my membership (which they charged me to do).  I tried reasoning with the manager, but he said there was nothing he could do and that they would not let me cancel my personal training membership until they had billed me 3 more times.  They aren't going to be able to do that because I blocked them with my credit card company.