I always put no canvasers on any car ad I put in and these tossers still phone me.
I find a simple "which part of no fucking canvasers dont you understand" seems to do the job .
I did have one company who called 4 times in the space of 24 hours even theough the first answer had been a polite but firm no.
Got their number on 1471 rang using a mates phone asking if they knew anyone selling the make and model of car I was selling as I was looking to buy, guy on the end of the phone got realy excited until I said oh nevermind I've found the car I'm looking for on ebay now bye