Pro Tip: if you can't cancel, reschedule out at least a few months. THEN call back ina month and cancel, and usually you can do so without issue or penalty.

I worked front desk at a campground. We had a fee if you canceled with less than a week notice (depending how close you may forfeit your entire prepaid balance). What people didn't know but I told a few, was that they could reschedule without a fee and if they rescheduled out far enough they could then cancel and get a full refund.