If you made the backup of the stock then it should still be recoverable. I have been using an old favorite, Ontrack's EasyRecovery Professional it searches for everything unlike some wares available today. I would connect the sdcard to the computer via a card read and run the software do an advanced recovery, select the drive then click next. If it didn't show up the I would try the deleted, formatted recoveries and last resort if you wanted to take it that far and is more difficult raw recovery, it doesn't always provide a file name and you are stuck with file size and possible a date. Please PM me if you need anything.