Prosecutors are not likely to assist these folks in collecting usurious debts. Call the prosecutor's office and see what they will do.
Please read my other answers regarding these types of payday loan collections. Often they are SCAMS. If a third party is attempting to collect a debt, they must send you a validation notice under the FDCPA within 5 days of their initial communication to you. You are not required to make any agreement to pay prior to receiving this notice. I just googled STP associates, and sure enough there is talk about it being a potential scam.
I agree with the answer previously as to many of these outfits are scams. Several of my clients have received threatening calls concerning very old defaulted payday loans. When I call them, they either don't answer or don't return the calls.
When you "Google" them, you see numerous other people have gotten calls from them and it is a scam. They are making threats, often involving criminal charges, which they don't intend to pursue. This likely violates the Federal Fair Debt Collection Practices Act and our Texas state Debt Collection Act. As I understand it, if you sue them these outfits will then relocate or just close down, making it very difficult or impossible to collect any judgment. I suggest you report them to the Texas Attorney General's Office and the Federal Trade Commission.
That being said, I understand that some payday lenders in some parts of Texas, notably the Valley, are filing charges and the prosecutors are accepting charges, for defaulted payday loans. To my knowledge that is not happening to any of my clients in the Houston area, as the prosecutors will not accept the charges.
We are a debt relief agency and we help people file for relief under the bankruptcy laws.