OP contact SOS!SEN. They started JR for DS1 when his indi ss placement failed and the LA washed their hands - EHCP is worthless, he will probably never attend school etc. He never did return to school but had a bespoke package for 20 hours private tuition, plus 1 hour each of OT, SALT, and specialist ASD counselling per week
Are you using specialist SEN solicitors?
The FB group EHCP experiences provides legal advice.
It is a crap and time consuming experience. Eg to bring Judicial Review proceedings against the LA for failure to implement the EHCP you really need a water tight EHCP with unambiguous wording (only usually achieved following tribunal).
I suspect that you are justifiably angry because you think the school are deliberately not meeting need knowing full well he will be overwhelmed and that his reactions to being overwhelmed will result in exclusion.
Ime schools would initially try to say 'no' to attendance based on the well being of other students but this is a difficult legal position as the school has to identify which pupils and exactly how they will be impacted. So schools are forced by the LA to take students they don't want because they have already spent their devolved SEN budget on the local offer and have not planned for meeting the first 6k of a new pupil with an EHCP. So they either say the EHCP exaggerates need (if the child internalises stress) or exclude the child and claim that what they have provided meets a wishy washy inadequate EHCP (if the child externalises). Either way the EHCP is not met.
Even following tribunal the EHCP is not met. Even after Tribunal, schools will not meet the EHCP. Secondary is even worse if the school is an academy. We had a Tribunal, legal support etc but still the school failed to implement the simplest of things. Unsurprisingly, the placement failed. The most stupid arguments will be accepted as valid reasons not to provide support - needs to learn independence, needs to learn not to be autistic or pass as NT because difference/disability won't be tolerated at work so can't be tolerated at school.
Having done several Tribunals, JR and numerous failed placements, m/s, ss etc I have concluded that mental health is for life (DS1 is now 19 and virtually housebound and has weekly hour long home visits from CAMHs (they go up to 25 with a diagnosis of ASD) and that education can take place out of school (DS2 attends internet school). On a personal level, I have had to give up work (educated to PG level) but we are all still alive. I don't say that glibly.
On a social/political level it is a scandal. Mothers on local FB groups still find the strength to campaign and help others despite the personal tragedy of their DC self harming, being admitted to mental health secure provision hundreds of miles from family and kept in isolation or even taking or losing their lives.
Thank you for posting in AIBU. If you have never experienced this, please empathise - surely you can imagine how you would feel if your child did not receive support for a diagnosed condition because the NHS was strapped for cash because failure to do so wasn't immediately life threatening eg a broken bone not being set leading to lifelong problems with mobility.