Received a call on my cell in the Denver area around 11:37am on 6/1/17.  I only use my cell with personal friends and emergency contacts.  I was expecting a call and answered this and it was a recording of a female saying something about a warranty expiring (no specification on company or what the warranty was for).  Clearly a scam.  I have also received calls from similar numbers in the last 24 hours, all starting with the same first 6 numbers (720-256-2574 and 720-256-5185).