CSV upload issues

I’m using the latest version of the Responsive Directory theme and am confused about the CSV upload. (By the way, I had posted this question in a diff forum earlier, but was told that this would be a better place for it.)

The issue is this: The user experience shown in the admin demo for the CSV upload (and in the video online) is quite different from what is actually available on my site. Primarily, it is not possible to make updates to the spreadsheet and then have them applied to the Listing in WordPress. All I can do is re-upload the CSV file, which then creates a duplicate of the Listings that have already been done.

Am I just missing something? Help, please.

Thanks!