Got a call, ignored it, no message left.

Same thing today, ignored it. No message left

fifth call in 2 weeks. no message

Don't worry about it. If  you don't recognize the number don't answer.  If it's important they'll leave a message.

Always got some calls like this when I just got a new Gophone number. they just tried to waste my minutes? I wander if the cell phone companies has something to do with this!! 360-322-6132, 240-212-0332.
I called back to 360-322-6132 and heard: Thanks for calling back....240-212-0332 was just music playing.