According to Consumerist, based on a thread at the DebtConsolidationCare forums, US National Bank somehow acquired a bunch of paid-off payday loan accounts and is trying to collect on them. And their threats are apparently working. The poster on DCC paid them $300 to avoid trouble—including the three felony counts he was threatened with.
If you get a call from US National Bank, don’t panic. Take careful notes, writing down everything they say to you. Get the name and phone number of the person calling, the account number they are collecting on, and the amount of the debt they are trying to collect. Record the call, if you can.
Then, call a consumer lawyer. Debt collectors cannot threaten you with jail time, cannot collect a debt you already paid, and cannot lie or otherwise harass you. If they do, you can recover $1,000, plus damages for the emotional stress caused by their harassment and threats, and the debt collector will have to pay your attorney.