WLS referred to as Cosmetic?

I am posting this in the cosmetic forum also, but I figured I would post here too.  I have Anthem BCBS, almost 6 years out from lap RNY, lost 150 and have maintained.

I am currently seeking  a corrective/reduction surgery for my breasts.  My PS submitted my preauthorization claim to my insurance (requesting mastopexy) and they came back with the correction/reduction is the result of a previous cosmetic surgery and that they will not cover it.  I have appealed and they have stuck to their decision.  I meet the requirements for reduction with documented neck and back pain over the past 2 years and hand problems. 

  I understand that some people seek WLS as a cosmetic self-pay procedure but mine was considered elective medically necessary and covered by my insurance (Tricare) at the time.   My current insurance also covers WLS as the only method to treat obesity. And I would have met their requirements to have the surgery.  How is it that they determined that it was a cosmetic procedure?