If you have a card reader, or can connect the camera to the pc you could try using 'PC inspector file recovery' this software is capable of recovering deleted files, or files lost during a 'quick' format. I have used it succesfuly to restore deletd files on my phone's memory card, and also on my camera memory card. Not sure where you can get hold of the software, but if you search the net you should find it or something similar.
It's not guaranteed to work, but you have nothing to lose. if it doesn't work, you could always try other software.