Hmm... It looks like they are gone forever now then. I can't think of any other way of getting them back apart from restoring from an iTunes or iCloud backup. Somebody else might be able to help but I think they're gone forever. I don't know why they were wiped from your iPod but it could be something to do with security. In the future I would recommend syncing to iTunes or iCloud to prevent it from happening again. You can always make a reservation at the Genius Bar and see what those guys can do because it seems that they are still there, they are just 'hidden' from view. http://concierge.apple.com/reservation/gb/en/techsupport/
P.S I'm sorry for the late reply
- Try restoring from iCloud backup. See that topic of:
- If you used PhotoStream then try getting them from your PhotoStream. See that topic of:
- Otherwise they are gone.