How do I find an advocate to help me with my dad's illness?

I couldn't say it better. Everything debmcd said was correct. I'd got your local ombudsman on it right away. Go to www.ltcombudsman.org and type in the Zip code or find this person on the state website. They are very helpful in these cases. You do need to buy time, so read Deb's answer carefully.
Carol

On Monday morning call and start asking for patient/guest services, patient advocacy, charge nurse for the unit he is one, the ombudsman representative, manager of social services. In fact you might start with the utilization review nurse and work your way though the list. Identify yourself as the caregiver and that he cannot be discharged to home. Medicare frowns on "bounce backs", but the hospital carries the burden not you. Even if your dad doesn't qualify for rehab again this admission should buy him some time in a skilled facility which should give you some planning room. As a long time nurse, I certainly agree that the system is not concerned about the caregiver, they are just trying to move patients though the system. You have to find individuals within the system that will help. It is a lot of work for families, almost a full time job. I hope you get some answers. If they are trying to discharge to home and your dad is competent and says " I will be fine, this is good", you are sunk. If on the other hand, he says "I can't manage, I am not safe I can't go", you are in a much better position.