Robocall -- But they actually do have a number which they will answer and try to get your credit card info ...Scam them back tie up their time until the FBI gets 'em.
(877) 398-2594
I get called from this number about once a month. When I answer I hear a ship's horn blow and then a message begins about how I have won 2 cruise tickets...I always hang up, but it is always at some annoying time.