Occaisionally, Excel can salvage most or all of the file that was in memory from the auto-backup file(s). There is no guarantee, but it can happen.
Depending on how much time and money you are willing to spend to recover the information, there is some chance that you can get it back.
If it is critical, I'd open a support incident with Microsoft. While it isn't cheap (I think around $800 US), it is the best chance you'll get.
If that doesn't work for you, I'd suggest visiting Woody to see what the folks there can offer. Some of the best technical folks in the world (that aren't employed by Microsoft) tend to hang out there.
It is often easier to recreate the information than to resurrect it. Keep in mind that no matter how you drag information "back from the grave", it has always been in the grave at that point, so it needs to be reguarded with suspicion until you review every bit of it carefully. It is almost always easier to just start over from a clean slate.