excel spreadsheet lost

[albreco]

I have a spreadsheet containing a lot of data. Last week I left my PC for half an hour, on my return the excel sheet no longer existed. I could not locate it, but in folder, the excel file had somehow transformed it self in to 242 kb FIL.

I have no idea how to repair - i have looked at various website(help) however, without any luck. 

Any help, ?

i have attached the file. 

 thanks 

[#2]

Click File, Open. At the bottom of the screen there is a button "Recover unsaved Workbooks".

[#3]

@Jan Karel Pieterse 

Thank u