Hi Noah!
Without looking at your actual data, I have to generalize here. Here are some things to consider:
-
Google is pulling the wrong address info from elsewhere on the web. This is a highly common scenario. NAP (name, address, phone number) inconsistencies can cause precisely the problem you are describing. You need to do a citation audit to see if you can find the client's name associated with the wrong location anywhere on the web and clean up any problems you find.
-
The client has a duplicate Google Places/+ Local listing that is associating them with this address. For more on this, read http://localsearchforum.catalystemarketing.com/google-duplicates-merges/8307-easiest-way-find-out-if-multiple-listings.html
My advice is to follow through on these first two steps. Then, if you cannot find any of the above issues, your next step would be to
-
Use the 'report a problem' link on your Google+ Local listing to report the issue. Give it a couple of weeks to see if you get anywhere.
-
Then, if no change has appeared, use the troubleshooter at https://support.google.com/places/troubleshooter/1386120?hl=en Select the radio button regarding wrong address and then the radio button that says you've already tried using 'report a problem' and this should lead you to the option to have a phone call with Google's phone support. They are getting very good at quick resolution of many issues. *BTW, if you have the new Google Places for Business Dashboard instead of the old one, you will need to use a new troubleshooter. I've only read about this, but can link you to a post about it if you need it. Please, let me know.
I hope this list of steps, though sort of complicated, will walk you through a process towards resolution.