Advice on what to include in medical appeal

I was just wondering if anyone has any advice/experience on what information to include in an appeal to my insurance company for a weight loss surgery. I got the run around back in the winter...I was told 3 times that it would be covered, and 3 times that it would not - once I was told yes AND no in the same conversation! I eventually just gave it a rest. August 2nd, however, our staff had a meeting with our insurance rep, and he said definately that it can be covered with a medical review, because he knows someone that has had it done under this policy. SO, last week when I went to my gynecologist, he actually asked ME about it - I've recently been diagnosed with Endometrial Hyperplasia with Atypia, and he feels that the weight is the reason for this, and will lead to endometrial cancer. SO...he's already written a letter to send to my insurance company. I was told at one point that it was a good idea to include a personal letter of my own, explaining why I wanted to have it done. However, I want to be sure I cover as many bases as possible as soon as possible, so if anyone has been through this, and has any suggestions on what to include, I would be very greatful! Thanks so much!

What is your insurance company, and why did they reject it.

The insurance is United Healthcare - Mississippi. And technically, they have not refused coverage. Any WLS is considered a written exclusion in this policy. However, there is a process through which it can be covered after a medical review (which is why I was getting conflicting information, initially). So, while this isn't technically an appeal because they've refused, it's an appeal requesting a medical review.