Innocent Fugitive from the TV Licence Inspector

Yesterday we got a Red Letter from the TV licencing people.  They wanted to tell us that THEY KNOW we are unlicensed and that they have informed the TV Licence Inspectors of our location and that the TV Licence Inspectors are authorised to use Sophisticated Detecting Equipment and that they may call around at any time during the day or night.  They didn't tell us that when they do call around we don't actually have to let them into the flat.  They also didn't actually ask us if we had a TV and they certainly didn't give us any way of telling them that we don't have one.  Well, on the back there is an address to write to if we don't own a TV and they say that once we've written they will confirm this later.  BUT it's not free-post so I don't see why we should pay for a stamp ourselves, or the paper and envelope to write to them with. 

Better for them to pay for The Inspector to come around and see us with his Sophisticated Detecting Equipment and waste his petrol.  Last year they did send a form saying "Hi, if you have a TV you need a licence... if not then send this part back to declare your TV-less existence", which my dad returned.  12 months later we start getting letters telling us that "as the new tenant" we need to buy a licence - giving no nice declaration form to sent back again.  They must have done some (flawed) maths on the total amount of TVs that have been sold over the last 12 months and calculated that EVERY SINGLE HOUSEHOLD in the UK now owns a TV.