I think your school stinks.
My son just turned 17. He did GREAT in school the last time he was there. He was in self-contained classes and got along with the students. It was one of the first times in his life that we had him behave at school - no calls, no leaving work, it was very nice. Despite that he was in and out of Residential Treatment Center (RTC)'s for years.
The Residential Treatment Center (RTC)'s we sent him to did not have accredited schools, hence no Carnegy units. I'm in SC here they have to have so many of the Carnegy units to graduate. This meant at 17 he would start off as a sophomore and graduate at 21. They (school district) went back over his IEP and decided to send him to that alternative adult ed school 3 days a week and some nights. In this process he took a test to see where he was in the GED spectrum of things. He did great in English, poor in math. The teacher at adult ed said she would work with him on his math to get him to get a GED certificate.
In the mean time, he did a crime, got arrested and spent time in Juvenille Hall. There he went to class also for GED related subjects. When he got out, he couldn't live with us, so we sent him to live at a group home. The small town didn't want "those types" of kids in their highschool. Basically meaning my son the jail bird. For two months I hounded someone about it. Then our caseworker got on the wagon and low and behold - a new school / class was formed, run by that school district but for kid basically no one wants. His teacher even called me to tell me he did well on the test. (I nearly fainted) no teacher ever called to tell me he's doing good. Always ALWAYS calls for bad.
I would start with your sons IEP and find out how in the world they pulled this off without him being suspended or going to self contained classes. Under the laws of most states he / and you have an obligation for him to be going to school or you can both go to jail for truancy. In my sons case it's part of his probation ordered by a very bloated judge.Bloated or constipated maybe, not sure.
IN any event every school district has a person that is in charge of the special education kids. You need to find out who that is and call them, make an appointment and get involved with figuring out what to do with your son.
There is a place for him, maybe not in your district, but MAKE them help you. That's what that IEP is for. If they are not meeting and maintaining the goals set forth by the IEP - they are at fault. Let them shoulder some of this responsibility and find out who you need to talk with.
Hope this helps.
I have hopes that from GED he will go on to some type of tech school or college.