Hi Miller W.

This is not an unusual occurrence and unfortunately there is not a guaranteed "Undo", unless you have an early version of the file
You can try this--> close your Punch program (don't save or change elements!)--> Go to your Windows Explorer--> Program Files--> Punch! (your program)--> Data--> you'll find some files called ProDataX.dat (X will be a number ProData1.dat, ProData2.dat, etc)--> copy these files to other folder--> rename each file as *.PRO--> ProData1.PRO, ProData2.PRO, etc
Open your Punch program and open one by one the files ProDataX.PRO you created (File--> Open..etc). Perhaps, one of them is your old file

Patricia