Hi Aimee,
I'm not sure if you're aware, but your full name is being advertised on the forum, so you may like to change this to a username.
I'm not sure other than whether you've not answered some questions correctly, as to why they would return it, but hopefully they'll send you a letter with this, advising why it's been returned back to yourself.
Chris.
Nothing on this board constitutes legal advice - always consult a professional about specific problems