Thanks for the words of encouragement, Billy & Hurn-ia.
NATS Recruitment left a message on my phone, informing me that it was company policy not to provide feedback on the tests. However, as hurn-ia suggested - there is no harm in writing - just the small cost of an envelope and a stamp - even if they don't reply. Might give them an incentive by providing them with a SAE!!!
I totally understand your concern regarding wasting time, Billy. That's what has annoyed me so much - I can't re-apply until next Sept (12 month gap between retesting- once again company policy!)...then if I get through the tests- it's a further wait to be invited to an interview......providing I jump that hurdle...an 18 month training course follows!!
However, you still have your interview to attend - so be positive and try and read up on ATC as much as you can. I've heard they ask you to do some mental arithmetic in your head, by asking some scenario questions involving Speed,Distance and Time Calcs.
May show you a picture of an aircraft, and ask you to identify the type.
I'm sure you'll be fine......all the best.