Although I'm sure that has happened before, I don't seriously think you could assume anytime something like this happens, it's from someone who knows you, that is a ridiculous assumption and a very negative outlook on life in general to assume such a thing.
Daniel, I'm not trying to tell you what to do, but I'll say this:
You are young. This won't be the first time something like this happens, so just look at it as a learning lesson, and not a lesson on how to gracefully accept a loss either. Maybe it will come to that in the end, but use this opportunity to learn what your options really are, you do have some options here.
I have read so many posts about UPS losing or breaking goods over the years I have lost count, must be in the hundreds, so although I can't tell you how to proceed from personal experience, if it happened to me today, I would go visit my top 10 favorite guitar/amp forums, go to their search engine, type in 'UPS Lost', and start reading threads.
I have read TONS of tips on what to do on these threads. Fortunately, I have not had to deal with it personally, but you will find many many many tips and clues as to how best to proceed from these threads...the information is right there for you, but you will have to invest the time and research, just like learning how to build guitars really.
Don't just accept it so easily, and don't get too angry, just approach it calmly and figure that there is no better time than now to learn how to deal with this, because it won't be the last time probably.
I really hope you look into it, don't give up, and either get your wood back or get reimbursed somehow.
Don't just take UPS' word for it and let it go at that, they do not always have the last word in these matters.
Oh I'm not angry, just a bit disappointed. I know I'll get my money back, the problem is I'll never see the wood, and it was a really really pretty piece of figured mahogany.