Tell unpleasant from abusive
A harsh review based on a real experience can’t be removed, even if it hurts. Google removes reviews that break its rules: abusive or hateful language, off-topic content, spam, conflict of interest, reviews from someone who wasn’t a customer.
Report the review
From your listing, open the review and use the option to flag it as inappropriate, choosing the reason that fits. Keep a screenshot of the review and the date.
Handling can take time and Google doesn’t always rule in your favour. If your report is rejected, you can appeal through the appeal form in the Google Business Profile help.
Meanwhile: reply calmly
A polite, factual, short public reply reassures future customers: “We couldn’t find any trace of this order, could you contact us at [contact]?”. No attacks, no accusations.
If it gets serious
Threats, harassment, repeated defamation: keep the evidence and get advice from a legal professional or a business owners’ organisation. I’m not giving legal advice here.
What not to do
Don’t fight back with fake positive reviews, or fake reviews about a competitor: it’s forbidden, risky, and it usually ends up showing.
The best protection is still a steady flow of real reviews: an unfair review weighs much less when it is surrounded by dozens of genuine ones.