You should always unmount any removable storage devices before unplugging them from the system. Sometimes your OS will keep critical files (mbr, swap) in your pc's ram to speed up access to the removable memory. These files need to be put back on to gain the access. This is all the recovery program is doing, rebuilding the file structure. Unfortunately, to get a quality return on your data, you're most likely going to have to use a paid version of a program.