There is a bunch of unidentified calls  to my smart phone coming from a series of numbers661 558-1007,1008,1012,1013,1017,1018,1029.   Their Modus operandi  is to call repeated times without listening to my message or leaving any.   I have tried calling back without success.  They have an answering system that allows you to push a button to remove yourself from the calling list but they don't ever announce who they are.