Dinner shows are not a $10 per person cancellation fee. The cancellation fee is the entire cost of the dinner show. Even if you are planning to pay with dining credits, it will ask you for a credit card to guarantee the reservation. Before you click to pay online, make absolutely sure that it is not charging you the full cost of the event. You must have a dining plan attached to your room reservation to be able to do this.
You don't even have any dining credits until you have actually checked in to your resort, and you don't spend them on a dinner show until the point where you pick up your tickets to the show. If you don't cancel more than 48 hours out, don't show up and don't pick up your tickets, the credit card you left as a guarantee will be charged the full cash cost of the event, but you'll still have your dining credits.