CID: Gardiner MT. According to another site, the Frankenmuth MI (yes, that's right) Police Dept on 7/21/16 announced this is a consumer energy scam on WNEW TV-5.
http://www.wnem.com/story/32500570/police-report-consumers-energy-fraud-calls
Never leaves a message, continues to call. I know these kind of calls will never stop. I figure it is a part of life, and won't allow their insanity etc ruin my day/life. At least I know my phone works :)