I Have Severe GERD And Have Been Suffering From It

I have severe GERD and have been suffering from it for years, I first had the Realize Band in 2009, then had a revision the the Gastric Sleeve in 2014 due to complications. Months after the revision, My Gerd got worse where I was prescribed medication and take it daily. Recently the meds stop helping and I suffer from reflux symptoms on a daily basis. My surgeon suggests bypass revision but my insurance says its not medically neccessary. What are my options now? Or how can I get my insurance to approve the surgery?