Hi Jason,
Unfortunately, with the cancellation policy options, even a moderate cancellation policy allows the guest to cancel within 2 days. This system is geared to make cancelling easy for guests and disappointing for hosts who offer their property in good faith that guests will honor their bookings. Many people will take advantage of free cancellations to look for a better deal until the last minute, but would take to the streets in protest if a host cancelled their booking at the last minute.
I believe this would not be a problem if everyone lived by the Golden Rule (do unto others etcetera) but since everyone doesn't, the best solution would be for Airbnb to not offer cancellation policies that are so slanted in favor of guests behaving badly. I think your luck will change, just hang in for awhile longer.