They Call, then Hang Up so you call them back to see who it is. Once you do that you can not add them to the "Do Not Call Registry" because YOU called THEM. It's a new scam way of Calling so they can't get put on the List.
Call back gets "Hi, this is Lisa (or Christy) with Reward Redemption...." It's a big SCAM. BBB has a warning for consumers. Read here: http://www.bbb.org/central-florida/business-r ... do-fl-171532464
If you're on the DNC list, please take a moment to report the call here:
https://complaints.donotcall.gov/complaint/complaintcheck.aspx