I've confirmed with the administrative staff that no backup is available for the account; unfortunately we won't be able to process a migration to premium due to this, although you would still be able to start fresh with a new account if you so choose. In the future, I would strongly recommend keeping your own backups of the files/databases present (while Premium does keep backups on its own, no service is 100% failure-proof, so it's strongly recommended that you keep your own backups as well).