I don't think so, because they chose to keep their child home...you couldn't have known tehy wouldn't be there, and they should know you spent the money beforehand. O Tell them to come pick up a cookie.
Over $2?! Really?! I would have told them to suck it up buttercup...but I guess that's why I'm not a teacher.
I like what a PP said...you thought the world was going to end or your child would get hurt...and now you're upset about $2?! Ugh.