Mr. Reichman used a program on another participant's computer called photorescue on his last Antarctica trip. This program was reported to be very good at recovering corrupt files from several kinds of camera memory chips. I ordered a copy and although I never needed it yet I tried reformatting cards, erasing files and it had no problem recovering all data. This program was under $40 US. You might try it by downloading it. Google photorescue and it will get you to the right place. You can try a demo for free but it will rescue but not save files. You then, if you like it, have to buy the fully functional copy and down load it. It is for both macs and windows.
Robert