Also are they a company or just scammers

Everything you need to know has been clearly explained to you.  I have provided links to government agencies where you can learn even more.  Now it it your turn to take that information, to read it, and to not only use it, but to learn what you should already know.

Crooks such as these are not really companies in any traditional or even legal sense.  If they are registered at all in the state they are in, it is with a PO Box or mail drop.  Especially the phony debt collectors, who are operating what is best called a Criminal Enterprise that is out to defraud the public.  Some may pay token taxes or fees, but it is not likely they are declaring the money they steal.  That is why they want to be paid in ways that are as untraceable as possible.

Does your local drug dealer pay taxes?  Contribute to SS, FICA or State Worker Comp/Disability funds?  Have 401k plans and offer major medical to 'employees'?  Vacation pay?  Well, this is the same thing.

These are bad guys.  Knowing who they are and how they function in detail is not very useful. Avoid and evade them.  Ignore and block the calls and report any harassment. These are liars and thieves.