What you have described here is depressingly common.
Some pointers;
"Because we don't have an LSA" is not a recognised reason to exclude a child.
Basically the school will be clueless as to how to deal with your child.
They cannot appear clueless, so they make her/his "behaviour" the problem rather than their inability to engage with him.
They focus on the negative behaviour and then give themselves permission to exclude.
If they can dump a load of guilt on you at the same time so much the better.
It can be helpfull to mention that you know the act says they must fund 20 (might be 25 - I forget) hours of education based activity for him/her every week. This would have to start the day after he was permanently excluded.
You mention this because, naturally, they will not provide it, but if you comissioned it and then tried to recover the costs from the LA they would have no defence at the county court since they have a statutory duty to deliver.
I have known this work exceedingly well for parents in the past. Mention that you would be suing the lead councilor for education at her/his home address if you really want to make them squirm....
I know it's not a nice thing to have to do but it can be a big help getting your yp's needs met.