Why is the school system failing our at risk students?

I have four children and three out of four are special ed. and I am seeing that they are not following the I.E.P. and it seems we have the meetings and they make me feel like my opinion doesn't matter nor what i think my child needs. my other child have been having difficulties in school and anger issues. last year he wouldn't go to school and was trauncy a lot so he went to an informal probation for it. then he fought in school in self defense and was charged for fighting in school. now he got expelled from the school because he was trying to go home and a teacher stopped him and asked for his cell phone and he wouldn't give it. he explained that he was going home already and that he had the dean's consent that he could consider after 6th period time to go home. so this teacher put his hands on my son's shoulder and my son got this teacher's hand off of him so because of this he got expelled. I don't understand that my son was trying this semester to do his best and do all his ignments and the administrators instead of helping my son they just seem that can not face a challenge and help troubled/problematic teens. why is the school failing our kids. I know it goes both ways but he was trying and look what happened