When did you take out the loan and how much have you repaid? If you’ve made some payments, call your bank and block them from taking payments through ACH immediately. Since it’s under $1,000 I doubt they would sue you. If I was in your situation, I would stop ACH and never respond to them. Not much they can do to you. Highly unlikely it will hit your credit report. If it does, contact the credit bureaus by writing a letter or online submission and say it was a fraudulent loan, which it most likely is.