Calls from this number and similar numbers almost every day.  No message left.  Suspicious!  unknown scammer in Fresno,CA area.

Just called, i didn't answer unknown number, they didn't leave message.

Got a call at 6:45 pm. I missed it , but no one left a message.

First called my cell phone, then about a half hour later, my landline.  No message.

It's the "Survey Telemarketer."  Block it.
Call back gets, "Thanks for calling.  The survey you were called for is now finished."  This robo "survey" is how the telemaggots get around the DNC regulations.  There is no survey just some nonsense questions from a robo.  You'll be offered a free something for completing the survey then asked for you credit card number.  It's a SCAM.  Block it.
http://www.ag.state.mn.us/consumer/Publications/SurveyScams.asp