Can you connect it to your computer with the short connector flex that came with it and access it that way.
I had a 520 until a couple of weeks ago, when I dropped it and cracked the screen whuch then would not respond. I could still see some of the functions, couldn't use it to phone but I did manage to transfer my photographs. If they take it away to fix it, the first thing they do is to delete all your personal stuff - phone numbers, photos, One Note and so on, so I hope you have your phone numbers somewhere else.
If you can get an upgrade to a 530 it is very similar but with imnprovements - better camera for one thing.