Planet Fitness blocked me from cancelling my account.

Planet Fitness blocked me from cancelling my account. The first time, about 3 months ago, they said "their systems were down" and said they would call me back. They never did. The second time, I tried to end my contract (end of this month), but because I had outstanding debt they refused to do so. I don't want to renew another year with this gym as I literally can't afford it.