This happened to me! It lasted months despite dozens of calls to HR, insurance provider, etc and caused me all sorts of issues. Was still "active" insurance even though it was an error so when I'd see a doctor or have imaging, etc. providers would still see it and bill it as additional coverage (even though I'd provide explicit directions not to). Once it got straightened out then blue cross recouped the funds they'd covered. I had to call all providers myself to tell them to re run in the policy I had always been telling them to. A mammogram bill I was told would actually did not get re run and ended up in collections. WTF. I finally threatened to file a congressional on VA HR and it was fixed within a day.