Thanks for the excellent replies. A good night's sleep has given me a bit more perspective on the whole thing. Perhaps I was one of those that was torn between answering the questions honestly and not making myself appear to be overly laid back or introverted. Clearly, there's not much point in trying to persuade them of anything. The decision has been made. But I will persist in trying to get feedback of some sort.
Gonzo: your comments make a lot of sense. Of course there's a risk that feedback will lead to candidate's lying next time. On the other hand, it would also give them an idea of how to improve their candidacy and make themselves a better asset to NATS. Plus, any fakers will surely be found out come the interviews...
Paperclip: It took about three weeks until the first email, advising me to take the personality test. It then took a further week before I was informed of the result. I believe there are issues with a new computer system...
Good luck!
Shugs: Well done! what sort of things did you do to improve your chances?
In fact, I'd appreciate any advice on how to use the year until the next application wisely. I'll definitely be giving it another shot.
Cheers