Question about a letter from insurance

[antsmith101 0]

I recieved a approval letter from Blue Cross of CA for surgery, so I had it on Dec 3rd, 2007.

Today I recieved a letter from Anthem Blue Cross (say at bottom of letter it a trade name of Blue Cross of CA). They said they have previously requested additional information of surgery and have determined with the information provided that no benefit is payable.

I'm going to call the doctor office tommorrow and also the insurance company but I dont understand what is going on.

How the hell they approve someone and have them go ahead with surgery then wait 2 months and deny them?

Only thing I can think of is cause my company moved to new insurance in JAN and maybe they pissed off