This is a robo call scam once you answer then a real person is suppose to get on the line and give the scam of the day. Just block it or do not answer also if you change your answering service to not pick up till 6 rings then it will not answer because most of these robo calls only ring 4 times before moving on.
Did not leave message. Dialed back and got a tape recorded message, "This is an urgent public service announcement about your current energy bill.." CLICK... no thanks. Same Scam, Different Number.