hi, I have the same situation but I have got the files back.
But most of all, you need to have the backup of your phone, the tools iExplorer ( https://macroplant.com/iexplorer ) can browse your iTunes backups, just download and open it, the iVault data directory is '/App/com.flowever.iValut/Library/user.files', you can export all of your photo and videos to your computer.
I hope it can help you.