As you work on your Excel file, Office creates a temporary version of the file as a backup. If you save the a File overwriting a previous version, you may be lucky and find a backup file in the temporary files.
With your Excel file open, select > "File" > Info
Select option "Recover Unsaved Workbooks"
If one is shown, choose the file in question and click to Open it.
If this is does not work, another option could be if your file is on a corporate network, contacting your IT people to see if they can recover an earlier version of your file.
Dave