Corrections are the most valuable thing you can send us. Machines do a lot of the assembling here, which makes a person pointing at something wrong unusually useful.
Want a company listed, your own included? The add a company form is the place. It asks for the handful of things that are genuinely hard to find second-hand, and it lands in the same queue a person reads.
Nothing submitted there shows up on the map by itself. Someone checks it against the company's own site first.
Reporting a correction? Send a link to the source that shows the right answer. It saves a round trip and gets the fix in sooner.
Please keep anything confidential out of the box. The form runs on a third-party service, which the privacy page explains.