I don't have any personal experience working out at the gym since it has become Blast/WOW, but my husband worked out there for years, and when we had to cancel (since we were moving overseas) it took months of haranguing before they stopped billing us. The billing kept going even after the personnel assured us everything had been taken care of. To be clear, this was with a plan where he was assured that he could cancel at any time, so it's not like we were trying to get out of a binding contract. (And even then, there is usually a special allowance if you are moving more than XX miles away from a gym of that company.) We eventually got our money back but it was a very shady process all around, between Blast/WOW (which sometimes seem like separate entities and sometimes not?) and their 3rd party billing servicer, ABC Financial.

He also felt like the general quality had declined since it was Bally's -- machines not being fixed, cleaning less often or less thoroughly. I don't think anyone should make decisions based on Yelp reviews, but it might be worth at least taking a look at them in this case.