According to time-line, you posted this question about a week ago, so even if you HAD some slight possibility to recover that file at the moment the "disaster" happened, by now quite probably there isn't any.
Anyway, may I give you some help to try and it might help you in the future.
1. Stop doing anything more with your computer. Each time you open a file, save a files, access Internet etc, your chance to recover lost information is LESS.
2. Get a recovery application. You have at this site 17 Free data recovery software tools
http://pcsupport.about.com/od/filerecovery/tp/free-file-recovery-programs.htm
I understand that the better is RECUVA
3. Run your recovery application form a different HD or form a pendrive. You haven't mentioned in what format was your lost file, presume it's RTF so try to recover RTF files!
What you can do with that "blank" WordPad file? Change extension to TXT and open it with Notepad and check if anything useful there.
Finally, WordPad is a basic word processor. and it has no file recovery procedure. If you can't have MS Office, you can get it's FREE alike, Open Office.