It sounds like he may have autism, and school have been totally unprofessional and not doing their jobs! I think you need to request to see the SENCO and ask her for a CAF form- this is a form the school can send to the local authority to request an assessment, but u r entitled to do it as well as a parent. I helped my friend get her son assessed, and we went to CFCS to get that done here, but i am not sure if that is just a local thing. Or u could try and go to the doctors, and ask him/her if there is anything they can do- u can request to be assessed i think through the docs or they will know where u can go or what u can do to get help. Could the hospital refer u to a educational psychologist?
The SENCO is the person to speak to, she should really be doing her job, and if there are other parents with children with autism who are being treated the same, then she is definitely not doing her job correctly, my friend had that problem here, she moved her son, he got diagnosed very quickly, got the help he needed and is doing extremely well. The problem is if u r enforcing things at home, and they are not backing u at school his behaviour will continue to worsen at school.
I hope u dont think i am overstepping the mark, i was/am a SENCO, mainly working with children when they first come into school, and it is a slightly different ballgame then as they are covered by so many more things. I have worked with children though up to 11.
I think u really need to speak to the SENCO, and if she is useless as to speak to the local senco team. It makes me so cross when schools are not doing their jobs, they are not helping your son and god knows how many other children, effectively they are going against every legislation that exists for schools!!! If u have major problems complain to the local education authority, that'll shake the school up a bit!!!!!
Sorry rant over!!! lol x