If the sector of memory that the file was saved on has already been written over by data that was created since then, it is lost. You may partially recover something, but it will be corrupted. When you "delete" something, it doesn't actually go anywhere, it just frees the space that it occupies, and basically allows other files, programs, etc. to write over that space. "Shredders" that you see out there simply go over these spaces and write over them repeated times, and that's how they make it so that data cannot be recovered, although with enough time and usage, this will happen naturally.
The sooner you try a recovery tool the better, since this eliminates chances that parts of that memory have been reused again already. If you did manage to recover it already and it was corrupt, then in all likelihood that's the way it is, I don't know of any program out there that can turn back time, although depending on the nature of the file, some can be reconstructed.
