I got that same number calling me and they do not leave messages. I do not even live in Detroit, so I don't know why that area code would affect me. I am a student if that is similar to anyone else?
I just got a call from this number this morning. They called twice but did not leave a message. When I called back it said it was a non-working number for DTE Energy Downtown Office and then hung up. We had a power outage yesterday morning (and we called them about the problem) and then it came back on 10 hours later. Maybe they were calling to check up.