I had a six month membership at San Diego Workout, which I joined because my then roommate was teaching there. At the end of six month I was moving to Mission Valley, so I went in to gym to cancel my membership in person. At that time I was told by the man at the front desk that "the person in charge of that is not in" and he asked me to write a note which he would get to the right person.
Later I saw charges from "St. Louis Workout" on my bank statement. I called the number and could not get through to anyone. I immediately contested the charge at my bank. Turns out that "St. Louis Workout" is San Diego Workout. They had not cancelled my membership! My mother had moved to Oregon and cancelled her membership over the phone... so I called SD Workout to do this. They said to call St. Louis. I called St. Louis and they told me that they never cancel over the phone and to call San Diego. When I told him I'd already written and called SD he studdered a little and said I'd have to write. I was driving at the time, so I asked him to call me right back and leave the mailing address on my voice mail. I never got a call back. I'm busy... but it looks like I'm really going to have to drive back up to Vista during business hours and write yet another letter. Even then I'm not sure how I'm ever going to be sure that they actually will cancel it.
My advice is that if you actually MUST sign up there, make sure that you keep xerox records of every transaction and watch your bills. Or better yet, don't join.