Unrecognised file format. How can I recover these photos

Have you ever tried to apply a data recovery program like a photo recovery freeware to retrieve all your inaccessible photos back?
http://www.freeware-fix.blogspot.com/2013/02/photo-recovery.html
This is a freeware that has offered four data recovery modes for users to restore all needed data back from a memory card or hard drive. It can thoroughly scan your camera memory card and do its utmost to get all your needed photos back successfully.
Read more detailed information of this freeware here:
http://www.freeware-fix.blogspot.com/2013/04/data-recovery.html

Do not take any more pictures, and remove the card from the camera to lessen the chance of you overwriting some important pictures or videos. There are very many freeware software options available to help you recover your files. Please see this article that reviews several of the better freeware recovery programs that you can try (and yes, these truly are freeware). You may need to use a card reader with these programs though.
AFTER you've recovered the photos, format the card in the camera using the camera's format feature to prevent this from happening again.