BCBS California Denied Hospital Stay after admitted through ER

Sorry in advance for the long post. I had a myomectomy surgery in May in Hospital “A”, after being seen in their Gyno Clinic. Few days later during the weekend I started to have fever. After contacting the Clinic they advised me to go to the nearest ER. Because the fever was getting higher I went to a hospital “B” that is 30 minutes from my house instead of the hospital “A” that is 1:15 hours away. Both hospitals are in-network for my Anthem PPO plan through my employer.

Reached hospital “B” with a 103F fever on Sunday. After a CT Scan in the emergency room, they tell me that my uterus had an infection, and was admitted to get IV antibiotics. After a couple of days at the hospital “B” and still getting peaks of fever, they found that the bacteria reached the blood. My medical report reports this as “Sepsis”.

After 5 days, the surgeon at Hospital A and the doctor at Hospital B agree that I need to be sent in ambulance to Hospital A, and I may need to get a hysterectomy if the infection could not be controlled. At the end the infection is controlled at Hospital A and I don’t need the hysterectomy (for now).

Now Anthem denied my stay at Hospital “B”. First I received the a denial letter (for a preauthorization) saying that it was not medical necessary because I hadn’t a fever over 105F or seizures. I called Anthem asking to appeal and they told me to wait for the claim to be completed. Just today I noticed that they denied the claim in their web portal too, and it is for several thousands dollars (it says I have to pay $0 but I am pretty sure the hospital will try to come to bill me). They have approved most of the claims of Hospital “A” for the same issue, so why one medically necessary but not the other? Now I regretting not going straight to Hospital A.

Any advise how to appeal it? In the webpage of hospital B I can see much of the annotations of my case, and then in the discharge notes it says the causes of my stay, one of them sepsis.