I'm so sorry to hear this and I know how this hurts,when my son was a little boy, the kids at his grammar school were so mean, always bullying him.
Looking back, I'm happy when hubby was told we had to move where his company was relocating,my son had a good experience at his high school and couldn't understand why in the begining I didn't want to move, that he found his new school to have nice kids going there.
It's sad that only his high school years are the only school years he can say he was happy at.
He is a commuter student now in college and happy, so I thank God now that we had to move.
Bullies and the parents that raise these hoodlums, suck.
I'm sending you warm wishes for peace,healing and good luck, for you and your child.
I really know how it hurts to see our children mistreated,especially when we teach them to be kind to others and treat them the way you'd want others to treat you,looking back I feel maybe I was wrong teaching him the "right" things to do when we live in a society where many kids are going wrong.
Don't feel funny to go to the principal of the school and tell him or her what's going on, otherwise they don't know and these monsters get away even more with their attacks on others.
Take care,
DE

(((((((((( Cyran0 and son )))))))))))