Blue Cross tried to deny us our inpatient the second time. It took a two hour phone call and a call from my doc but it too was paid in full. I really think you need to appeal and maybe contact the insurance commission in your state. We also have gone in as an admit direct from the ER. Then they could not refuse service. I know there is a patient in Fla (I think at Joe Dimmagio??) that did the same thing.
We have not been to Dr S. Our inpatient is done in DC and inpatient was done in NYC. The only doctor that I know that does not take insurance is Dr Kirkpatrick in Tampa.
RSDSA.org has a list of ketamine doctors. The list grows every week!