Preserve the listing first
Record the exact Google Maps/Profile URL, displayed business name, address or service-area presentation, phone, website and date observed.
Use lawful public sources
Compare the listing with the company website, public business records and other openly available sources. Do not trespass or impersonate a customer to manufacture evidence.
Separate observations from inference
“The listing displays X address” is an observation. “The company does not operate there” requires support. Write those as different statements.
Check the relevant Google rule
Google says eligible businesses generally must make in-person customer contact and provides additional rules for business locations and representation.
Build a reproducible file
A reviewer should be able to follow your URLs, screenshots, dates and explanation and independently understand why the location deserves review.
Evidence standard: Preserve what you observed, identify the source, distinguish inference from fact, and use current official Google policy when preparing a complaint.