"We do not cancel or change any reservation through a web mail request.
Please call Customer Service at 877-612-1100 about this reservation."
I called the number and held until someone picked up. It was very smooth, the gentleman was very nice about it, and I was provided a full refund of the $31.00 I was charged for my one site for the 13th through the 15th. I was not charged a $9.00 cancellation fee.
I don't know if Eric L has had any luck in getting them to automatically refund all of us which have made reservations for the invalid date, but if it turns out you need to call yourself, do it quickly just to be sure you don't run into any technicalities that cause your call experience to be more difficult.
I will continue to be a Reserve America customer, and am looking forward to a summer of camping here-and-there.
Luck to you all,