Why does Google keep changing our business address back?

This is the single most frustrating problem in local search, and it's almost never a bug. Google reverts your edit because other sources it trusts disagree with you. Old directory listings, an aggregator feed, a data provider that sold your old address to forty sites, a duplicate profile you forgot existed, user-suggested edits.

The order to fix it in

1. Find the duplicates first. A second profile with the old address will undo every edit you make on the first one.
2. Fix the aggregators and the top directories, because those feed everything downstream. Correcting forty small sites while the source still says the old address is mopping with the tap on.
3. Make your own site agree with itself. Footer, contact page, location page and schema all showing the same NAP, exactly.
4. Then edit the profile, and it tends to hold.

The city-line problem

If your building sits near a municipal boundary, Google may assign you the neighbouring town's name. You can't argue it. What you can do is make every other signal consistent — profile, citations, site, schema — so the trail points one way instead of two.

On one pest control account this work took citations from 8 live to 29, cleaned 26 of 52 listings, and moved them to #1 for all three target terms in a quarter. The highest-impact fix was the least glamorous: the profile had the wrong city on it.