How to get data back on iPhones?

I recently got an iPhone 5s, and started to use it as soon as I got it. I filled in my contacts and camera roll, and after that I plugged it into my computer, restored it, and now it's gone.
Probably not the smartest idea on my part, but I want to know if there's any way I can get the data back.

Usually there should be a backup prior to restoring. Check in iTunes - Edit - Preferences - Devices tab
See if you have earlier backups.

If you do you're in luck. Try to perform a restore and select restore from backup (the earlier backup).

Here's a support article on apple for perhaps restoring from iCloud as well:
http://support.apple.com/.../kb/HT1766