HandsAcrossTime

I am from one of the schools that Brown buys plane tickets for (underrep minorities at the school). Brown bought me a plane ticket, but I can't go anymore. I had an emergency come up that I found out about on Wednesday (a few hours after Brown actually purchased the ticket for me). I tried to find other ways to get around it, but...alas, there are none that are feasible/that I can afford.

I talked to the travel agency to see if I could switch up flights, but they said they were no longer buying tickets, and I'd have to pay, which I definitely can't do.

So, what can I do? I'm okay with not going, but I feel really bad b/c they bought a ticket for me. Will they bill me for the ticket if I don't show up? Should I tell them? I don't want to tell even them the specifics of why I can't go because it is personal...but I just feel terrible. :[ They bought me a ticket, and I'm afraid I'll get billed for it if I don't show up...

Advice?