If you can't get them to move over on the phone alone (some apps just don't want to help), you can always connect the phone to a computer. Then move the photos over to a folder on the computer where you can organize them as you wish and then copy them over to the SD card.
NOTE: The reason I say 'copy' them over to the SD card is that you should really save a copy on the computer, or to a cloud account. It is way to easy to lose photos by deleting them (not on purpose), losing the phone, the phone is stolen, the phone dies, etc.