iron infusion appeal question

My insurance has denied my iron infusions-- anyone have any experience with appealing this?

I am 8 years out of surgery with healthy labs-- except my iron.  It was fine for the first several years post op but dropped to very low levels a few years ago.  I tried extra iron and C (separate from my other vits) for several months, eat lots of red meat, switched to cast iron cookware etc but no luck. Hematologist recc I get iron infusions as I simply was not absorbing the iron normally.  The infusions have been great- energy restored, my ferritin in the normal range again and sleeping well.  When my hemoglobin, hematocrit and MCV drop into the low range (and ferritin dips to 12ish) I get another infusion.  Works out to one infusion of venofer every 4 months.  

I live overseas so must pay my physician then file a claim for reimbursement with Cigna IntL.  Anyone have any luck appealing iron infusion medical claims?  I sent a letter from my physician stating that they were medically necessary already- no luck.  I have one more chance to appeal.  

Suggestions welcome.

Your best bet would be to call a billing office maybe for a hematology office, and ask if they would be willing to give you a little advice. They should be able to tell you how to code it correctly.