Sorry I only just came across this now. First let me tell you that things are not worse here than in the States. You may just have encountered a bad bunch in a problemed school, but I was a victim of bullying as a kid in the States and let me tell you it was hell until my mother got fed up and took matters into her own hands. Now I'm not suggesting anyone needs to follow this example but for what it's worth this is what she did:
First she told me that the next time the bullying started up I was to find the largest stick, rock, lunchbox whatever, and hit the little bastard up the side of the head as hard as I could. In other words fight dirty. Obviously I would be in trouble for doing such a thing but as we had been to the Principal’s office so many times as the victim, the bully's actions towards me were well documented. Being a passive child I couldn't bring myself to do this, but I felt empowered knowing I could let rip. Strangely this helped as the way I carried myself changed.
Second - my mother waited for the kid one day and cornered him. Very quickly but very strongly she told him that if he ever came near me again she would beat the life out of him. She let him know that he had pushed her to this point and she had nothing to loose. She also told him that if anyone else ever came near me she come after him.
I don't know if my mother would have actually carried any of these threats out, but she made sure he believed she would. I was never bothered again and the coward never mentioned it to anyone.
My son got some heat from kids when he first started in school here but he always hid behind the fact that his mother is Dutch. Kids didn't care and still gave him hell for his accent. Eventually I had a 10 year old and his father making fun of me and my son one day after school. I stood there smiling at him. The other parents were horrified. The idiot finally asked me what part of "America" I was from. I walked right up to him and got into his face and with crazy eyes told him I was from New York where we knew how to make f***ers like him disappear. My bluff worked as he backed down and said he was only joking. I told him I wasn't. My son never heard from that kid again.
Sometimes it's not about the power you have but about the power others perceive you to have. You can't allow your son to be a victim and I'm advocating he become violent himself. Perhaps the little bastards just need to know that his Mom is completely crazy