I'm so sorry your going through this. I understand how frustrating insurance company's and hospital staff can be. Sending prayers your way.
My daughter was in a terrible car accident almost 7 years ago in May and sustained a severe brain injury. She was in a coma for 7 months, went to a sub acute rehab and then a long term rehab (also Health South here in Memphis) where, like Dom, she received all three disciplines of therapy daily. After the insurance decided she plateaued, they tried to send her to the most horrible nursing home, so we declined. No other facilities would take her as she was still considered "minimally conscience".
At that point we had no other choice but to bring her home. She was still on her PEG feeding tube, couldn't walk, talk or communicate in any way. She also didn't pass her swallow test so she was not allowed to even have a sip of water! It was a VERY scary time for us as we had no medical training or experience.
With the help of Medicaid, we were able to have a home health care aid take care of her during the day so DH & I could still work. We put on a BBQ fund raiser for her and raised enough to have OT, PT and speech come to our house 5 days a week for the next 4 months. During that time I noticed she was "awakening" slowly like a newborn growing up. I decided to start her over again like an infant and re-teach how to eat with baby food, walk by DH holding her up and walking on my feet, etc.. After another 3 months we were able to remove the feeding tube.
She'll never be the pre-accident girl she was before, she has Ataxia on her left side so her walking is still wobbly and her hand spasms, her speech is impaired due to a paralyzed vocal fold, her short term memory lasts less than a day, but she now has learned to text herself anything important.
To make a long story short, 7 years later she is walking, talking, eating, going out with friends again, volunteers at the animal shelter. She has a great quality of life and it keeps getting better slowly. (We're trying to find her a job now!)
Don't ever give up, even after this long improvements are possible.