Can we sue an insurance company for this? [Oregon]

Posted on r/legaladvice was told to try posting here as well

Some background and I’m on mobile sorry for any formatting…

My grandmother (Late 70s F) was recently in the hospital due to a bladder infection which made her very weak. She was falling on a near consistent basis about 3-4 times a week before she was admitted. After her stay in the hospital She was sent to a special care facility for her to regain strength in her arms and legs. We were told by the facility’s staff that she is mentally no longer able to live on her own. We had known for a long while that her memory was going but it had gotten progressively worse and then took a nosedive while she was in the hospital.

Here is where the problem lies…per her insurance company she was approved for up to 100 days in the care facility. Last Thursday while we were discussing options for future care and getting ready to sell her home. We get a call from the care facility stating that she is to be discharged Sun Dec 4th (Today as I’m typing this) because her insurance has decided to stop payment to the facility. My mother has since sent up two appeals to the facility’s decision which seem to have been ignored because we didn’t hear back on those.

When my mother tried calling her insurance company (She has POA) the only reason we got from them is that “it’s too expensive” according to my mother. We have temporary accommodations set up for my GM and she is being moved to a long term care facility on Tuesday this week.

My question is do we have a leg to stand on in court if we pursue legal action for all this?