Getting custody of a younger sibling?

My brother is in a *bad* living situation with my mother. She doesn't buy him food, doesn't make sure he's clean, and has clean clothes. She's always taking him to the hospital and keeping him out of school b/c he's "sick." She's got two pending charges for child abandonment, and child endangerment. He called me last night crying, my mother brought two men home from the bar and you could literally hear them having in the background. I'm afraid for his safety, but Dfcs WILL NOT help me at all. They keep giving him back to her even though she's extremely unfit to be a mother. I don't know what to do anymore, or for that matter where to even begin trying to help him! I'm in nursing school, I work and I have a child of my own. I just don't know what to do! Any tips or advice?