Dynamic Recovery Solutions scamming to send money for debt not owed Greenville South Carolina

Received letter from Dynamic Recovery Solutions stating I currently owed 636.04 to someone named ASSOCIATES.  I do not know who this is, I do not owe anyone that amount of money and I'm hoping it's not on any of my credit reports.  The current owner is Fitzgerald Equity Partners, LLC.  I have contacted Fitzgerald and told them to send me a copy of the bill, who it is from, itemized and when this occurred.  Awaiting response right now.  They want you to submit a letter to their office within 30 days to get a copy of the judgement.  They need to at least let you know who they're using to scam you.