Hello John, I know about an outstanding (but not very famous) program to recover the FAT when is corrupted. If FAT recovery fails, it can search for the folders and bring them back.
I've attached the program on this post, but if you don't trust it you can download it by yourself.
Instructions:
0) Extract all files from the zip on a new folder, plug your damaged card in
1) Run testdisk_win.exe. Run it as administrator if you are on W7
A small console will open, but don't worry you don't have to type any command, it's a step by step Wizard.
2) Using the arrows select No Log and hit ENTER
3) Select the flash stick and hit ENTER
4) On partition table type select Intel, works most times. Hit ENTER
5) On the list select Analyze and hit ENTER
Existent partitions will show up, but don't select anything on them, notice that the option "Quick Search" below is marked
6) Hit ENTER to access that option
7) Your lost partition will appear on green
8) Press P to list the existing files
From now you can see your files and the instructions to handle them: a to select all, c to select file, mayus + C to copy the selected files, etc.
The saved files will be copied by default on the program folder
If you have questions or need moe help just ask
Best Regards