Help on filing insurance

 I am looking into Dr. Gagner for my revision.  He has asked me to get a name and number of someone with my insurance concerning my surgery.  Do I call the 1-800 number and ask for a case worker.  I have the procedure codes so do I start there.  I guess he is still setting up his office and no insurance person.  I have asked to speak with is staff and all I get is an email telling me to do it.  So if anyone knows where I need to start please let me know.  Thanks