I NEED SOME HELP

I RECIEVED A FAX TODAY FROM MY HEALTH INS STATING THAT THEY WILL NOT COVER MY APPOINTMENT WITH DR ARGOTTE BECAUSE THEY HAD 3 DRS THAT WERE APPROVED, ONE IS IN ST. LOUISE AND 2 AT CARLE CLINIC, WELL I DONT WANT TO GO TO THOSE PLACES I WANT TO SEE DR ARGOTTE. SO I CALLED MY INS CO AND DR ARGOTTE'S OFFICE AND TALKED TO CINDY AND SHE SAID I COULD MAKE AN APPEAL SO I DID THAT . SO NOW WHAT I AM WONDERING IS IF I SHOULD WRITE THE LETTER TO THE INSURANCE CO ALSO. PLEASE HELP ME IF POSSIBLE I AM TOTALLY DEVISTATED!! NANETTE