To amplify a bit on Vicky and Sammie's comments, there are a lot of factors in a
DVC points reservation that only the owner will know. I'll highlight a few of the main difficulties an owner faces in trying to help a renter whose plans have changed.
Points time restrictions - There are two key time considerations with DVC points. The first is that each year's allotment of points is valid for exactly one year. If the points used for your reservation are approaching expiration, the owner may lose the points entirely in the event of a cancellation.
The other consideration is the banking window. Owners can bank points into the next Use Year only during the first 8 months of their use year. If that banking deadline has passed, the usefullness to the owner of the points is drastically reduced.
Another time consideration comes up when a reservation is canceled within 31 days of arrival. In that case, the points from that cancellation can only be used to book a reservation 60 days in advance -- a very difficult task with DVC.
Reservations availability - You can call your favorite hotel just about any time and get a reservation, but that is not the case with most timeshares and definitely not the case with DVC resorts at WDW. DVC reservations can be made as far as 11 months in advance, and during many times of the year, they
must be made 11 months in advance. Depending on the resort and the specific dates, the owner may have ZERO ability to put the points back in their account and just rent a new reservation. The same holds true if you wanted to change the dates of your trip -- there may simply be nothing available.
The owner could just change the name on the reservation to someone else, but obviously they would have to find someone who wanted
exactly the same type of accommodations for
exactly the same dates and that's trying to find a needle in a haystack.
There are many other considerations, but I think you get the point. Regardless of what an owner
wants to do to help you, they may very well have NO
ability to help.