What can I do when my father calls home from hospital multiple times every night demanding to go home?

You know what I would do, I would take my dad something to eat that he likes, sit on the hospital bed with him as he eats. I'd look him in the eye and talk to him. I'd tell him, 'I know this stinks dad, I know you want to go home, but you CAN'T. Just as soon as you can, I will tell you.' I think it's funny that the dad says he wants to get out of the hospital and 'eat something' which is why I would bring him his favorite food (if at all possible) to start the conversation.

In my opinion, no, the hospital really can't forbid a paying client from exercising his right to make a call. Whether or not the call is answered, though, is another story. Is the son close enough to visit daily? A visit, with a loving reassurance given with touch (I find my Dementia clients "hear" me better when I touch them), may help calm him. Leave a note by the phone. "Dad, I know you'd like to call me. I am out this evening but we will talk tomorrow" That way, the hospital worker can simply read the son's message with your father in law, rather than forbid him to call. It's up to the son, then, to not answer the phone if it rings. Just an idea.