Can someone clear this up please?

On the letters I keep getting pestering me for a TV licence they contradict themselves by stating you need one for watching films/DVD's etc, then further down it ends with "so if you use a TV to recieve or record a broadcast signal then you require a licence"

So which is it?

I've told them to fuck off loads of times and they keep telling me they are sending someone round but in 3 years I've never had anyone show up, but if they do I dont want to look like a mug if he says I need one. But common sense tells me that its only if you use the broadcast signal you need to cough up, if I'm using it for a games console or to watch a film then I've already paid for the right to do that.