I received several emails from RECOVERY@500FASTCASH.COM indicating that I owed a substantial amount of money. I did remember using them many years ago (2004 or 2005) and I am 90% sure I had already paid them. I made the mistake of contacting them about the account and agreeing to pay a "settlement" without first asking for an address or doing research online. After my debit card was authorized, I started researching and only found negative references to 500 FastCash and Pinion North, the company that charged my debit card. I caught it in time and had my bank stop the transaction.
I called the number back and asked for a mailing address but they refused. Very sketchy. I think Pinion North is likely fraudulent. I can't seem to find a valid business license with the secretary of state either.
Also, I am constantly and consistently reviewing my 3 credit bureau reports and nothing has ever appeared from 500 FastCash or Pinion North, making me more suspicious of their dealings. If they have a legitimate claim against me, they can report it to the credit bureaus - the way all other credit and debt collectors do business.
Make sure you document everything, including your phone calls.