Does your country allow suing him for a large monetary amount? Have you talked to the media? A lawyer? Maybe together with others? Made it as easy as possible for the police to get him, paper trail, receipts and all?

You do have points, though, but there might at least be some actions that you and others can take in this case. Maybe a medium change like changing the law on this specific point might make sense.

I'm not law enforcement. This shouldn't be my job. If I see someone robbing a store with a mask on and a gun I should be able to call the police, report it, and hand it off.

If there's an accumulation of complaints against this merchant then that should warrant an investigation.

The police have like half the local city budget, can't they do their job?