no message left, I called the number back and got a brief recorded voice: "NUMBER NOT FOUND" then it disconnected.
so if they are using a spoofed number or have set up call-backs that way this is some kind of scam and not a legitimate business.
They said they could lower my ComEd electric bill and wanted info from off my statement. I told him I was at work and he was very insistent and said he could get ComEd customer service on the line to get the information. When I said, I was not comfortable with that, he seemed to get agitated and telling me not to hang up ... so the only response to that is ... to hang up. I blocked the number as it sounded fishy ... or should I say phishy.