Once you start writing to the card you have written over the old files and rebuilding is never going to happen. Files that were not overwritten might come back but you appear to not be using common RAW or JPEG files so recovery prospects are dim.
Try the many items noted at http://pcwin.com/software/Secure_Digital_Recovery/index-2.htm
I have formatted a cf card with valuable raw files on. Before I realised my mistake I wrote 6 new files to the card.
When recovering, I can only see the six new files. I am also getting tif and .exe files. The files I wiped were .cr2. Is there a way to rebuild the cr2 files from the .exe and .tif flies.
Thanks in advance.