I checked, and it looks like you have posted this information on your ticket. I'll go ahead and follow-up with the team about this so that they check. Thanks!
You're trying to be fair, but processing the request will likely cost Upwork more than the amount involved. That's the reason why you've got the money in the first place - to make the issue go away.
The best you can do for a positive impact is to minimize your inteactions with support staff - which means to just keep the money and move on.
An even smarter choice would have been to reconsider the entire situation when the client changed their mind and asked for the files. At that point you should have factored into the price all the mess they created and charge accordingly.