My mother was kicked out of her nursing home without proper notice. Any recourse?

My 90 year mother with Alzheimer's was recently admitted to a geriatric psychiatric ward at the request of her nursing home. She has been at the ward for a week and a half and has been getting much better. At the nursing home, she was agitated and would have outburst with some of the staff telling her to do things. We also have learned that some of the medications which they having her take were adding to her agitation. Last Friday morning I met with mother's Dr and we discussed how she have improved. She was the best I had seen her in months. Her Dr was hoping to discharge her on Monday. Everything seemed to be going well until I received a call Friday afternoon from mom's nursing home. They called to tell me they would not taking my mother back. I was in shock. But I also thought if they were not willing to take her, it would not be in her interest to force the home. The social worker from the hospital was also shocked and in disbelief. Her comment was... the nursing home has not even been to do an assessment of her mother since she has been here. I spent the weekend looking at nursing homes suggested by the social worker and we thing we have found a good place but it is significantly further away. I am not interesting in suing the nursing home. I am interested in making a complaint so a regulatory body can look into the way they deliver care to the elderly and vulnerable. Any suggestions or other such experiences?