It seems these guys call from the following phone numbers:

6139630473
6139630474
6132162467
6139630521
6139630522

http://800notes.com/Phone.aspx/1-613-963-0473
http://800notes.com/Phone.aspx/1-613-963-0474
http://800notes.com/Phone.aspx/1-613-216-2467
http://800notes.com/Phone.aspx/1-613-963-0521
http://800notes.com/Phone.aspx/1-613-963-0522