Timeshares essentially pit one member against another. This is the way all timeshares work that have a reservation component. The rules of engagement are put in place by the state, POS and management company. As I noted on another thread, I think changes should be a cancelation and rebooking thus stopping much of the walking but not necessarily all. The only way to stop it completely (or as nearly as possible is to have changes as a cancelation/rebook on separate calls with a certain amount of elapsed time and/or to institute fees related to such changes.