I too have heard problems with advantage plans. Dr.'s are recommending them because the Advantage plans relieve the drs. of the paperwork. I suspect the paperwork is missing and no one is being honest with you.
Here's what I know about handling insurance companies since the affordable health care plan came on board:
Intermediaries consolidate your paperwork and submit.
So you have to figure out FIRST why it was rejected so YOU can take responsibility to get it approved.
I have had SO MANY things bounced - but nothing is EVER bounced if
1) you know what diagnostic codes are needed by the insurance company
2) your doctor and the advantage people have included the correct ones
3) you have gone through the required protocol. This means you have done things in the order they want to see it done, and all the MRIs, Xrays, etc are submitted to show the history
4) know this: YOUR HISTORY is not kept on file anymore by anyone (thank HIPPA for that!)
Therefore - you must keep a copy of your paperwork to give to the submitting doctor.
I once had a lame doctor who was superbad and paying attention. My back surgery was rejected. I drove over to the office with a half inch of history on my back, it was faxed over and the next day my surgery was approved. Then the doctor dropped me but it was for the best - I ended up with the worlds BEST surgeon who told me he repaired all the other surgeons BADLY DONE SURGERIES! (OMG!)
unfortunately, we have to be the administrative secretaries for our own bodies these days!
P.S. - I had 4 opinions on my lumbar spine condition from "sprained" to complete back replacement from cervical to tailbone and a neurosurgeon who would have waited until I pooped on myself. My surgeon turned out to be the L3, L4, L5 guy with fusion/laminectomy. Took me 18 years to get there. Maybe the Universe is trying to help you get to the right thing. Hang in there. Low-dose Opioids helped me deal with the pain while I waited to get to the right place the Universe wanted me to be! I'm SO happy I got through it, you will too! don't give up. Work on your own behalf. That is what helped me get thru it the most!