Debt Settlement Letter

Received a debt settlement letter, dated 5/24/2021, from Andrew Law Firm, for the company Advance Cash Services.  Letter states that I owe them $1385.00, but they will settle for $850 today or two payments of $485.00. I don't know this company and don't recall obtaining a loan from them.  I don't know the law firm, called Andrew Law Firm (firmandrew5@gmail.com).  They are threatening to garnish wages and have me arrested.