Samsung Customer Service told me that there's nothing they can do. My phone updated automatically and I didn't get a chance to backup some very important files. The woman mentioned that nobody else had reported such a problem, as I did it moments after I updated and couldn't find a single thread about it. Now that I see it's happened to others, perhaps they'll try to work out a solution.
I'm keeping the files as they are for the time being in hopes of getting a fix. If anybody hears anything, please let us know. I'd be immensely grateful.