Yet another phone survey

What are the Rules?

What they may ask you when they telephone you and ask questions?  The other day I spent half an hour trying to convince someone that I really didn’t have a cell phone that required me to buy an extra so many megs an hour or whatever it was because I didn’t need one and because for somebody my age it was not a good idea to start a new technology like that. Yesterday, at supper time of course, the phone rang again and a voice at the other end said they wanted to ask me a few questions I said go ahead; first question they asked me was how old are you I had no objection telling them I was 88 years old. The next question was what are the first 3 digits of my postal code. I said I’m not telling you that and they said why not. Its none of your business. I said;  tell me please who you are asking on behalf of ? Who are you doing this survey for and they replied they’re not allowed to do that! I cannot believe there really are rules that say when you make a survey of people you can’t tell them who’s making it; so I told them  you tell the person who is making this survey day that if he tells me who he is I will share  my post code is or at least the first 3 digits of it. They said we can’t do that and I said in which case why don’t you simply tell the person who requires the survey to take a long walk off a short pier.

What are the rules anyway?.