Where is the file stored? On a shared network drive? If so you may be able to use shadow copy (Previous versions) to recover your file. Right click on the folder it lives in and see if you have a previous versions tab. Then you can select the day you want to go back to and copy the file out.
If not is the folder backedup by a nightly or weekly backup job? If so have your network administrator restore it from backup.
Finally if all else fails look for files in the same directory ads your file that start with ~ these are temporary files and one of them may contain your data.
Good luck and make sure you always have a solid backup.