Lost mail

...has finally arrived. More than two months ago I mailed a fat envelope to R at her school. It contained a money order from the US Postal Service to pay for an exam she needed to take. When it didn't arrive a few days later, we had to go through the whole process again of filling out the test forms, getting another money order (they wouldn't take a check) and sending it priority (in order to make the deadline). Well, R took the test weeks ago, and yesterday the errant envelope finally arrived in her mailbox at school. Now I'm wondering if I can get my $100 back for the money order. I'm also wondering where that thing was for two months.