Mom was appointed a guardian against her will. I am her oldest child and was not notified of any hearing nor was my mother. How do I help?

She was at Integris Canadian valley hospital in Yukon OK. I had stayed there with her for 3 weeks and this hospital knew my number and knew I was coming to get my mom and they gave her a court appointed guardian and placed her against her will with no notification to me into a long term care facility in El Reno OK. Please someone help me. My mom is dying alone and scared and we have to get permission just to speak to her over a phone!
The hospital told her they were moving her to a skilled nursing facility for rehab on her legs, but she has had no therapy and is placed as long term care. Please help me.