I am going through the exact same thing with Cigna. However, on my 3 month nut, I was told FOUR different times that all I needed was the receipt from online weight watchers. I also had 2 months of dietician through Cigna's on wellness group for 2 months last summer. I have to do WW online because we are so far out in the country, there is no class. ( those are from Cigna rep & insurance clerk)
After denial it goes to -"reconsideration" -My pcp letter was sent again on Thursday and now suddenly at 3 pm on Friday, my surgery is cancelled.
They are having a peer to peer on Monday a.m. to try and resolve it. But Cigna is obviously just trying to screw people over. When I spoke to Cigna Thursday all they needed then was the PCP clearance.
But, by the insurance dept not having all my paperwork the first time, they denied it- not medically necessary. Then they denied it again Thursday night/ Friday morning because of this "missing paperwork"
So, all this has caused a denial on original, a denial on reconsideration and probably a denial on appeal.
Just make sure to continue doing their job for them. Otherwise, Cigna will screw you.