Lost source data can data be retrieved

HELPPPPPP!!!!
I have worked non-stop obviously too late at night last night. I ended up wiping out 400 entries in an excel spreadsheet. Project due Monday morning, job hangs on this.

I can still do a pivot report against the 'saved' data. So it must be out there in a file...? I read the function GETPIVOTDATA. Based on the description, It sounds like it would work to rebuild the source data. However the examples given don't see to match up with that. I have tried playing with the command, but I really don't know what I am doing and have had no luck

Does anyone know of a way to retrieve that stored data that the pivot reports are reporting against????