How do I get insurance for lap band or byp surgery if my insurance company has turned me down.?

My insurance company will not cover lap band surgery for me (or gastric byp for that matter). I have been overweight for years, have sleep apnea, sore knees, and the necessary BMI to qualify. Even the hospital that would do the surgery has told me that they turned them down. Paying for it myself would be out of the question. My company has been using this insurance company for years and years - I do not see them switching carriers in the near future. Is there any way I can get this surgery done? I feel the pros far outweigh the cons.