You should ring ACE for advice on that, essbee. Are they doing it a lot? Regular unofficial exclusions like this will probably put intolerable pressure on you and may leave no official record which you can use to lobby for alternative provision/extra support. They are not legal, last time I looked. If they can't meet his needs they need to say exactly why not and what is needed, not just send him home. I'm sure the school are doing this because they are sympathetic to his distress and understand he is not being deliberately naughty but actually it can backfire. It could be better for them to officially exclude him. I do think you should check it out with ACE. He's entitled to an education and you need the break from him.