Please don't press anything when you get calls like this. All that does is confirm that your phone number has a live person (=possible sucker) at the other end. Threatening to report them does NOTHING. They know they are untraceable; they live (if you can call it living) somewhere in a mud hole overseas, where the DNC and the FTC and the FCC have no authority to do anything.
Best response: NONE. Don't answer again, don't engage them in any conversation, NEVER call back; get a call blocker if they calls persist to the point of being annoying.
Called my cell. Didn't recognize. Didn't answer.
http://www.whitepages.com/phone/1-312-971-2602
Bandwidth SMSEnabled VoIP in Chicago, IL
Moderate spam activity suspected.