From what you have said tonight, the first and foremost task for Bindmans is to tackle is the issue of visiting and funding for your journeys.
Your boy is a child and, furthermore, he is 300+ miles away from his home and family. He needs the reassurance of regular face to face contact with his dm and other famly members and I can think of no more cruel and unusual punishment than to deny a child a visit from his mother at a time when he is, allegedly*, extremely unwell.
Given that your son was so obviously upset and disturbed by what a sw told him that he attempted suicide, I would have thought that his clinicians and all involved in his treatment would be begging you to visit him and, to my mind, your LA should be laying on a chauffeur driven limousine to transport you to and from his placement we'll get it, honey!.
To clarify, as I understand it your ds is no longer on a forensic ward. If he was first sectioned in late September his 6 month section is overdue for renewal. It's my understanding that, should a psychiatrist deem it necessary, he can be detained on a further 6 month section after which time 12 month sections can be imposed.
As a confirmed cynic realist and given the timing, I am given to wonder whether the sw's visit came about at the hospital's request and whether there was a review or other meeting between her, as a representive of your LA, and Ardenleigh personnel** to which you were deliberately not invited.
I would suggest that Bindmans make the necessary enquiries and, if they have not already done so, request copies of your ds's health and social services records as a matter of urgency.
*I've used the word 'allegedly' because although I do not dispute that your son is, and has been for some considerable time, a very angry and unhappy boy who engages in self-destructive behaviour, I am not convinced that his psychiatric dxs have paid sufficient attention to the possibility that his 'symptoms' are caused by the frustration of an ads child who has lacked educational and other provisions that would have met his needs and may have materially affected his behaviour since he reached puberty, and before.
This is coming to the core of the matter which is whether his behaviour is attributable to psychosis or whether it is not uncommon in adolescent ads who are driven by hormonal changes.
To the best of your knowledge, prior to his admission to Ardenleigh, has your ds been assessed by a psychiatrist who specialises in autism/Asperger's on a regular basis or at any time?
**It is not unusual for clinicians and other medical personnel to be unaware of the legal difference between a child who is looked after on a voluntary basis and one who is in the full care of a LA by virtue of a court Order.