Should I be able to get my money back if I ask for it back during an intermission of a play?

Tonight I was watching a student play at my school, but it was horrible. It was very boring and the actors weren’t very good, so at intermission I went back to the box office and asked to have a refund. They acted like they didn’t know what to do and then they said no because I had already watched half of the show.

I’ve never walked out of a play before, but I’ve walked out of a movie half-way through and gotten my money back, so I figured I could do that. Am I wrong? Is it tradition in theater that if you watch at least half the show you have to pay for the whole thing?