Since OP thinks it could be a scammer doing it, perhaps just check the referral ...

		tisryno on June 20, 2020 \| parent \| context \| favorite \| on: Ask HN: Google won't remove my site URL from rando... Since OP thinks it could be a scammer doing it, perhaps just check the referral header and display a big banner stating that listing on Maps is not you and to not contact them and list real services/competitors? Will stop people from contacting them in favour of real businesses if that's the case.

I agree that this is better, it punishes Google's reputation as well.