Hi Customer! I'm sorry to hear about the issue you're having with a corrupted file. Unless you had either manually saved "versions" of the file as you worked on it or backed up the file somewhere else, there isn't a good way to recover this file. However, here's a bit of a "hack-y" method that may recover some of it:
Open a new file in OpenOffice, and then choose INSERT -> FILE from the top menu. Select the file you're having trouble with, and attempt to insert it into the new document. Depending on the amount of file corruption, this may bring in some of all of the contents of your file.
It's a bit of a long shot, to be very honest, but I've got my fingers crossed for you! Kindly let me know if that works.
I'm sorry to hear that. In that case, I regret that the contents of the file will be unrecoverable.