Just a couple of clarifications based on what little I know of what you guys are talking about.
SSDI recipients are on Medicare, not Medicaid. And there is a two year wait to get on that, I believe from the date of disability. For SSI recipients, it's Medicaid, only to the disabled person, not to the family.
You don't need to go through the guardianship process in order to be designated recipient of a disabled child's (no matter the age) SSI check. I assume the same applies to a over 18 child collecting SSDI as dependent of SSDI recipient.
Dreamer, in order to consider your daughter a child disabled before 18 presumably they would have to determine that she is disabled. Even if they determined that she was disabled years ago, at the 18th BD they have to do it again. There are certain exceptions such as genetic conditions eg Down's. But if she's not in one of those categories presumably they have to review her records and possibly evaluate her to determine that she is disabled.
In terms of hospital treatment, I'm confused as to how the hospital can wiggle out of giving "charity care". If you qualify you qualify. That does not include non-medical charges such as TV and phone in room but should include all medical charges.
I have had success in getting the local office phone number and an extension from a person in that office when I'm there. eg I owe them some Dr name or phone number and I need their number to call them tomorrow to give them that info. I also have been successful in getting the 800 number people to put me through to the local office by making them sorry they even tried to address my extremely complex question. LOL. Also, when you do get the local office phone to answer try pressing buttons like 0 and the star and pound signs. Might get an office directory or something. Another thought, while the default office is the one assigned to you, you can ask that all your files be transferred to another SS office that is less busy if there is another near you.