I also received a call from this number saying it was from United Healthcare. I was told my claim was from a  provider that was out of network and I would be receiving a check in the mail. I heard that, knowing it was not true, and hung up.  

united healthcare

Had call from this number and they left msg saying to call back and put in a certain extension #.  I did, (we do have insurance with United Health Care, and that's who they said it was), and it was pertaining to a claim that had been submitted.