I still have a membership to Planet Fitness from 5 years ago that charges to my account every month
while I had no problem signing up online, you can only cancel your membership in person at your "home" location, or by sending them a certified mail letter formally request cancellation (which I have tried and failed apparently because I never heard back)
I now live on the other side of the country, so it feels ridiculous to spend money on a flight ticket just to cancel a gym membership
worse, Planet Fitness requires you provide bank account/routing number for payment, so there is no way to cancel payment unless I switch bank accounts