I'm not sure if this would help, but have you considered trying to add Local Business metadata to the site that Google can pick up?
It's possible that it'd overwrite the other business entry, or you might be able to report the business as a duplicate. At the very least, you might end up with both showing up stacked instead of just the one so you might reduce how many people interact with the fraudulent listing.
It's possible that it'd overwrite the other business entry, or you might be able to report the business as a duplicate. At the very least, you might end up with both showing up stacked instead of just the one so you might reduce how many people interact with the fraudulent listing.