Looking for film title.

Hi,i'm looking for the title of a film that i watched a couple of years ago, Not sure when it actually came out though. The premise was along the lines of a mother who had her troubled teenage son bundled into the back of a van(essentialy kidnapped) and sent off to some kind of 'boot camp'. I think there was a bus load of young men who arrived. It turns pit it was run by a horrible l9ad of people,mainly the one in charge. The young men were beaten,sexually abused,etc. I think the main young man who was taken in the beginning ended up killing his abuser. Its a great film,and i may be wrong but i think its a one word title. Hopefully someone will know which film im talking about as i would love to watch it again!