It's kind of hard to play hard ball with companies like these. Because the debt is owed no matter what, and when companies tack on high interest fees, and threaten, it makes it even harder to lodge a complaint, or clear your credit by ignoring them.
They know they have the higher power when they don't tell you who they really are. However, over time with all the complaints that get made and with everyones sneaky investigative work we can find out who they are.
While filing your complaint, tell them the next time they call that you find it hard to believe they are a real company when they have no website, no address to mail a certified check to, no local phone number to call, or any other information that can validate the debt to you.
This company is still in hot water. Keep all receipts and documents if you send anything to them. Record the calls if you must. In some states, recording the call on incoming lines is ok. In situations where outgoing calls are placed, you need to announce it.
Regards-
Mike