Just received a call this morning from this number.  I do NOT answer any calls where the ID is "Blocked", "Unknown", "Unavailable", Anonymous" or "Out Of Area" or I don't recognize the caller ID.  The caller ID on this call was "OTTAWA   ON", no name and then the number.  Since we know people in Ottawa, I called the number back twice and both times I received the, "This Number Is Not In Service". "Please Check The Number and Dial Again"!  From what has been reported here, I see that it s a scam.

CALLS EVERYDAY... leaves no message. I called back requesting to be removed

File a complaint with the FCC Online here:  http://esupport.fcc.gov/complaints.htm  

These people should be shut down because they use automated machines and do not allow you to tell them to stop.  Their mailbox is "full."

Phone rang, I always look at the id first, it was (613) 216-2172 in Ottawahull, ON.  I know no one there so I ignored it and the phone stopped ringing.  In a few minutes, the message waiting light on the phone turned on indicating that a new voice mail was stored.  Checked vm, silence, but I saved it anyway just in case.

It's a scam.  Shows (613) 216-2172 "Ontario" on caller ID.  They are tryomng to get your credit card information.  File an online complaint with the FTC here:
http://esupport.fcc.gov/complaints.htm

Have received numerous calls also.  I called back from my home phone and got a message that the number was disconnected.  Called from my cell and work phones and got a message "I'm a big jerk and I leave erroneous telephone calls with no messages".  He is a big jerk and he does make erroneous telephone calls with no messages.