Claiming that I defaulted on a loan

These people are crazy I got an email from these a holes!threatening me with jail time and fraud and other so called charges for a loan that I supposedly defaulted on which is a lie they claim I have to appear in some court to pay 3,000.00 plus dollars or two payments of 800.00 and if I don't I can go to jail for 3 years but they won't tell the name of the loan company or show me any court papers that they claim to have already filed but I don't have any court orders to be in court ,and when I told them to show me proof of their claim ,I want stamped court orders and their bbb rating and business license number ,I was told they would be proceeding with a law suit against me so what do I do this is BS and I don't have time for all this somebody help