Hi,
Sorry for this set-back. I do not have the same insurance co. but encounter the same comment for the first refusal. I had the doctor re-do his letter. He made it like a table format and had columns for dates, diet prescribed (Atkins, WW, etc.), weight, comments. In conclusion he showed that I tried 3 different diets with some minimal weight loss and gaining back on the first 2 diets, and that served to proove that I could not succeed in any weight loss program without a WLS. It worked.
Good luck to you, keep fighting the insurance co. because if your surgery is not excluded, it is just a matter of formality and to give them all the necessary/right paperwork... like a government agency!
Ciao... for now.