Basically they work on the principle (surely) that every household in this day and age must have a TV and therefore should be paying a license. If you haven't got one, they'll send someone round, send you a letter with red print on it etc etc until you buy one. They will be tenacious and diligent in their pursuit of any non payers. This is of course unless you are living in privately rented accomodation, are a student, on the dole, are quite big and fierce looking and likely to kick someone's head in if they try and get into your house, or can legitimately claim that the name they have on the piece of paper is infact not you and that this particular person fecked off back to whereever he came from months ago (it does help with the last one if you are not from the UK and can passably pretend that you can't speak the lingo).
Another sure fire way of throwing a spanner in the works of any government agency is to send them a cheque long before they actually come knocking on your door. When you do, simply don't sign it and put down the wrong address of your home (your aunt's or something will do). Then fire them an email or two periodically saying "I'd like a reciept if it's not too much trouble

When the sh!t does finally hit the fan, you instantly go into one about council/government incompetance, producing cheque stubs, records of emails etc etc and it'll really put the cat among the pigeons. After a couple of months when they've checked back through all the records, files, waste paper bins and deleted inboxes they'll get back to you. It's at this point you throw in the "and what about the other cheque I sent FFS!!!". Obviously since the whole episode began, the vast majority of personel who ever worked in the office at the time will long since have embezzled enough funds to feck off somewhere warm and sweaty, so it'll take them ages to get to the bottom of the whole saga, if indeed they ever do.
If they do ever return with a comprehensible proposal as to how you are ever going to pay them, you dispute that a) you ever lived in the property they are referring to b) that any of the correspondance is actually from you in the first place and/or that c) you were out of the country at the time. If all this fails in the end, you either pay up, or feck off somewhere warm and sweaty yourself for a bit until they've forgotten about the whole thing (couple of months ought to do it).