How to stop elderly from leaving assisted living?

I am an adult grandchild and have helped manage my grandmothers care for the last 5 yrs because others like my mother refuse to help her anymore because of her behavior. I love her tremendously and since she moved into assisted living she has improved so much. Though she is young (70's) she has extensive mental illness that requires her to have care in a 24/7 facility. She is unable to handle her medications and when on her own she often has accidents. For instance when on her own in an apartment she severely burnt her hand on a candle and started a fire by knocking it over. Additionally her mental state is not always sane she has constant mood swings because of her Bipolar and Schizophrenia. The problem is she is the most active and youngest person in the facility. Combine this with her mood swings and she is constantly complaining. She disrupts the staff and picks fights with them causing problems. Then uses the problems as a reason to need to leave. The facility management have continuous problems with her and my other family members just wont do anything. I want her to stay so that she has freedom to some degree because of her age and ability to stay active. However, she insists on leaving and continuously calls me on this issue daily. When I speak to other family members about it they think she should be moved to a nursing home. When I speak to management at the facility they tell me they think she needs to be in a nursing home due to her behavior. For instance staying up all night in the lounge playing piano in a nightgown and being rude to staff. What can I say or do to help her understand? I have suggested to her to talk to her doctor about it and I try to stay positive but she is adamant.