Unwilling to honor their contract of providing a 100% covered preventive procedure. I researched and successfully countered each of their varying reasons for denial. They were either unable or unwilling to give the real reason. A message left for a supervisor was never returned. After hours on the phone with multiple agents over 3 days,and my refusal to hang up, they finally let me talk to a supervisor who said it was a specific medical coding error by the doctor. We'll see if they honor their contract with the corrected claim.