Let's look at both sides of the equation.

1) One signs a legal agreement so one is obliged to pay.

2) One signs up for a product/service where "every time you go, it is full". That could mean a non-fulfillment of contract and non-delivery of service as per the agreement.

I'm no lawyer, but one can make it clear that one wants all the facts to go very public about why one is unhappy about the product/service offered, as a defence, if one gets sued. Also mention that you would want to make it very public so that everybody knows that if you sign up with them and then change your mind, they will sue you.

Whether they want to go ahead and sue, well, it's up to them.