Excluded-Unless Medically Necessary???

Ok, I finally called my insurance comp, BCBSNJ and was told it was "excluded unless it was medically necessary". She told me I needed a predetermination letter by my PCP. I have a 48.1 BMI with several comorbidities including Type 2 Diabetes. The medically necessary part is definitely there. What worries me is the "excluded unless it was medically necessary" part. I have read all around my insurance book. I didn't see anything about WLS. Even in the exclusions section.

Has anyone come across this situation or verbiage in your insurance book? If so, were you approved?

Thanks,

Gina