Paul_foley
I had the same problem. I had to send numerous emails, but the one they replied to was the one where I contacted them through the careers website, rather than replying to the email to which they tell you to reply to (if that made any sense, lol!).
Anyway, it took me 3 months to get from sending in my application, to getting invited to take the tests!
Persevere and pester them! You will eventually get a reply!
Good luck,
binbrain