Screwed by a client

I was contacted by a school… a christian school at that, wanting to talk to me about helping them with their website. I had a meeting with them and brought a couple mock-ups for them to look at because they initially just wanted me to update their html site because their web guy quit. The site was unbelievably terrible, just awful. So I proposed a new site. A few weeks went by and nothing, I wrote an email to see if they were still wanting a site and another couple weeks went by. I went to their site today and they have a completely new site! And it looks JUST LIKE THE MOCK-UP I GAVE THEM! It is much more amateur than what I did, but is a complete rip off.

What should I do?