They've been calling several times each week, day and night, leaving no VM message. I finally called the number back--before blocking it. Got a recording with no identifying information, but saying that I should press "1" to be removed from their calling list. If you do this, many telemarketers consider it a contact YOU'VE initiated with them, which gives them the "right" to call you back endlessly...or at least this is their (mis)interpretation. Don't do it unless you have call-blocking capability. You'll never get rid of these pests!