Bottom feeder collection agency, Credit Adjustments Inc, out of Defiance, OH who also uses a Manchester, New Hampshire PO Box address.
If you look up their address at 330 Florence Avenue in Defiance, Ohio, they operate out of some old warehouse. Nice.
Credit Adjustments has had multiple class-action lawsuits against them for violating the Fair Debt Collection Practices Act (FDCPA). They will resort to any tactic to harass you.
I would highly recommend not answering your phone and do not call them back, or they will never leave you alone. They play dirty and not by the books, as evidenced by the large number of lawsuits and complaints against them.
Change your phone number if they won't leave you alone. Be sure to also file a complaint with your State Attorney General, also file a complaint with the Consumer Financial Protection Bureau (CFPB), and the Better Business Bureau.
We CAN and will put them out of business for harassing consumers, and this has happened with other collection agencies when enough of us file complaints.
Be as relentless toward them as they are toward you. There is strength in numbers and we as consumers can fight back against their harassment.
Use every means necessary and available to you to file multiple complaints. We WILL stop them if you do this.