My mother is incontinent and refuses to wear protective undergarments. Has anyone else had this problem?

My mother is 89 and has Alzheimer's disease. She has become incontinent at night and during the day. She is still considered to be Independent in assisted living because she is very ambulatory and does not need help with dressing or feeding, etc. She is constantly walking around with urine soaked pants and her bed smells terrible. My sisters change it regularly, but her carpet is now foul smelling. We pay a small fortune to keep her in this facility. She refuses to wear Depends or any other protective undergarments, during the day or at night. I have a plastic mattress cover on her bed. We removed all of her regular panties and replaced them with pull on protective panties, but she does not wear them. I live in another state and cannot surpervise her. The assisted living home says unless she is in the "Assisted" category, they can't do anything, and even then, I don't think they can force her to wear them. Has anyone else had this problem? I am at my wit's end.