It does seem like some people are taking the mick...I don't get why though!?
It could have something to do with the fact that your post states that this is an "Amazing Domain" with "MASSIVE Potential" not to mention the fact that you say it MUST sell tonight before stating that you're going to extend this sale by another 7days on sedo if you get £45. So, actually, you don't think it must sell tonight...
But I wouldn't worry...
The hard reality is that this is not an Amazing Domain - it's a Poor Domain with almost no potential.
You are right that there are loads of uses for K"A"T and there are many millions of Google results. But which internet savvy business, individual or trader is going to choose K4T.co.uk as their ultimate alternative to KAT.co.uk?
On a number plate, K4T or K4THY could be something quite nice if that's the kind of thing a Kathy or Kathy's boyfriend would like to buy. Doesn't have the same appeal on the web. Seems to me that you have to rely on an organisation called "something K" 4 "something T". There's a site in the States called "Kids4Truth", for example, who own k4t.com. But one or two weak hopes in a whole world wide web hardly gives "MASSIVE Potential with this one!"
I know this is not an appraisal thread but you did ask why the others are making fun of you and, although I may very well be wrong, this is what immediately springs to mind.
Just saying it how I see it - not intending to cause any offence and I'm very sorry if I do. But a good hard dose of reality can sometimes be a good thing in the domain world...
Good luck with building your domain portfolio and see you around on AD.
Best wishes, Richard