Struggling to get la to agree to fund equipment

It's a long story but local NHS won't provide appropriate equipment due to "criteria"

Private assesment occured and was found to be needed,a clinical letter was written and provided as evidence

La contacted a NHS provison of what exactly we have no idea and why

Which was promptly rejected as they seemed to be pediatrics and only take under 16 (Op here is 18+)

Any mention of it now has been removed from EHCP and provisons and that the LA will not fund it,to go to adult social care

It falls under a health need and a provision needed to acsess education so how can it be up to social care to fund..?