When you go to the contact page to get the number to unsubscribe, if you hang out for a few seconds an option to talk to someone over chat eventually pops up.

When you go to the contact page to get the number to unsubscribe, if you hang out for a few seconds an option to talk to someone over chat eventually pops up. They'll try to keep you, hard sell you on other services, etc. just keep saying you'd like to cancel and they'll eventually do it. It'd still be nice to have a one-click option, but at least it's a bit easier to do passively than needing to call someone.