Rissachu

I was in a shop where it said things were free (I'm new).. and when I click on the item it says "do you want to but blah blah from for 0L" or something like that.. I click yes. And then I do it a few more times other objects and then I look up at all of my L cash is gone! It was cash put on there by an instructor for my college to snap photos for an online class that takes place in Second Life. How is it possible that something that says it's free has taken my money?