Sorry about your problem – sounds extremely frustrating.
What we do is back up our original camera files in three places..when the project is finished we purge 2 of the 2 back-ups, but keep #3 indefinitely – partially because of issues like what you’re describing – but mostly becasue a client may want a revision someday.
If by any chance you have a set of the original files, bring them into your computer and have Premiere link to those files instead of the renamed files, and you might be in luck.
Otherwise, unfortunately you may have to choose between 2 tough options – manually renaming the clips, or starting the project over.