I don't get bothered much by cold callers at the door but did have one a couple of years ago who got a bit irate because I wouldn't buy his "fresh" fish. When I said I didn't buy things out of vans he said everything was delivered to a supermarket in a van!!
A friend who does get a lot of cold callers has printed off a sign from the internet which says "If you are not coffee, bacon or chocolate - I need you to go away!" It may not work but it does make her smile!
As for the people who ring saying they are doing a survey, I interrupt and ask how much they will be paying me. They will sell the results of the survey or use the answers to make money in some way - they usually just hang up!
The next thread for friendship, advice and support if estrangement has affected your life
Water Pollution -“ A National Disgrace”? A case for renationalisation?