denied need help

I was denied by Fiserv Health because my "BMI was not over 40 for the last 3 years"  It has been 36 to as high as 40.  My insurance plan document does not state that you have to have BMI greater than 40 for 3 years.  I was told by insurance that "it is a general guideline"  My surgeon's office has never had this happen before.  If I appeal do I stand a chance?  How can they deny me for wording that is not in my plan?

Most insurance covers for BMI of 40 or greater, or a BMI of 35 or greather if you have 2 co-morbid conditions. If you have 2 co-morbid conditions and a BMI > 35, I'd definitely appeal!