Google Local prefers our competitor

[Looncoot]

We are Green Widgets at 2470 Some St. Our competitor, Little Red Widgets is down the block at 2486 Some St in the same building. All the big directories (InfoUSA, SuperPages, etc) have our correct address but Google Local shows us at our competitor's address.

Worst of all, if I search for Widgets in our zip, Google shows our competitor but we do not appear at all so Google seems to know which company is REALLY at that address.

Is there any way to persuade them to fix it? I have sent email to local-listings several times over a period of many months but it doesn't change.

Thanks,
Looncoot