Lap band questions-please help?

ok so I have been thinking about getting the lap band for over a year now and have decided that this is the right choice for me. I am over weight and meet the BMI requirements for this surgery. my doctor submitted the request for me and it was denied. When I asked my medical group why they said that it was because I have to show them that I tried to lose weight and failed for a period of six months. When I asked how I was supposed to do this they said that i would need to sign up for such programs as nutri-system, weight watchers, etc. i explained to them that I could not afford these programs for six months because they are very expensive. They said that this was the only way to prove that i was on a diet. Can anyone think of a way that I could prove that I was on a diet for six months. My doctor stated that I was and they still wanted proof. I have Anthem Blue cross HMO and if approved this surgery is 100% free. Also I heard that the requirements for the lap band have changed. Does anyone know what the changes are?