WP Smush - Lost images

My client used WP Smush to bulk smush her images. However, she was at her disk space limit and it looks like all of the files were uploaded with zero data. I talked with support yesterday and they suggested using the revert thumbnails plugin. After trying the plugin, nothing has happened. She still has the original files in her file manager. How can we revert to earlier smushed version of her images that have data?