Prior Authorization for Surgery Denied me for a Wrong Reason

This is through work insurance. I have a chronic condition that I have had to have surgery for twice so far. Once in 1998. Once in 2006. I need it again. It was always paid for as a congenital condition. I don’t have the same insurance of course and my old doctor who did the surgeries has retired. She was on her own and has left no info on how to get ahold of her.

My current insurance denied this surgery based on the fact that the previous surgeries “were elective and not paid for” (approximately what they said.) I know this isn’t true.

My current surgeon said he’d go out of his way to help me, but now is saying there’s nothing he can do, and just pay the $9000 in cash for the procedure. U fortunately, I have a slim amount of records from then, and nothing from the company I had that approved it.

I know where the previous surgeries were. I know my current doctor could write a freaking letter.

Does anyone have ANY advice? I know it was 18 & 26 years ago but someone should have something in the next 40 days (time to appeal.) I’m going to contact my insurance tomorrow from back then and the facility where it was done. They should have an approval letter. Anything I’m missing? I found this out 2 days before surgery and was devastated. Especially because their own reasoning, in their denial letter, is 100% incorrect and my doctor has just thrown his hands up even though she can read the SAME LETTER.

Thank you for any advice!!