My condolences on the funeral.
I just arrived at Beaver, sorry I couldn't respond earlier to give you a little more time.
If you are an Elite member, then you can cancel up to the day before and be credited the entire amount minus a $5 processing fee. If you are not an elite member, you could have also mailed in a credit request form and at the discretion of the director you would have been credited the amount paid minus a $45 fee. These policies are all in the rider manual.
http://www.nesba.com/Info/Downloads/manual.pdf
Unfortunately, it is almost too late to do something about it now unless you are an elite member.
You can still sign up for Sunday if there is room, but you would have to pay. The mail-in account credit would have taken a couple of weeks to process and you wouldn't have had the credit in time to register for another event.
Hope this answers some of the policy questions.