You do not say at what stage you failed at...Did you not work hard enough at the book work, or was it the practical side which you found difficult?
I failed basic, but I passed the book work, and my fail was a very subjective one, based primarily, I felt, on character judgements rather than ability. There were others who had similar difficulties and were passed/given recourses. I know I'm not alone in this kind of experience within NATS, unfortunately there is too much of a grey area when judging trainees, not enought clarity/black and white.