the best way to deal with these is the method i use which i believe was linked onto here a while ago from youtube
providing you have plenty of spare time to mess about with them... without ever telling the caller you're a cop (therefore never actually impersonating one, cos thats illegal), you tell the caller that they've just rang the scene of a serious crime
I did this recently, asking the person what business they have with the occupant of this house (me), how long they have known (me) the victim, and when they come up with the excuse that they pick numbers at random by going off postcode records I then said "but you asked for this person (me) by name so you must have personal dealings with them" then i asked them for their company details, asking where their head office is based and a personal contact number to contact this guy at his own home. he then put his superior on, and I asked him to put the first guy on as he'd asked for me personally
they hung up
