I think this is just some BS phishing stuff.
A company sent my brother a letter saying that he owed them roughly $500 for some bill related to a domain he never owned. The company is out of Toronto and not even USA based.
Just wanted to give everyone a heads up to watch out for this kind of crap. They were trying to tell him that he had some sort of oversight and that he owed them money. Just be careful about paying bills that people send you that you do not think are legit. There are some crooked people mining who-is info out there.
Just like email, they probably figure if they send out enough letters, someone will pay them on some bogus debt. If this company is somehow legit, then he is the victim of id theft. The domain in question is not even in the archive.org database and is not currently registered either… very strange.