The facts that you describe are that someone loaned you money and that you have not paid it back on time. Unless there are other relevant facts that you have not included, it is very unlikely that there is any basis for criminal charges. North Carolina does not put people in jail for defaulting on loans.
It is not uncommon for payday loan companies to make false threats of criminal charges. Any collection calls that include false threats of jail over debts may violate state law. You can read the North Carolina laws on debt collection here: http://www.ncga.state.nc.us/EnactedLegislation/Statutes/HTML/ByArticle/Chapter_75/Article_2.html. Violation of state debt collection laws can carry money damages for the victim of up to $4,000 per violation.
In addition, North Carolina has strict laws about payday lending. The loan that was made to you may not have been legal. If so, the lender may also be violating the law by trying to collect payments.
If you believe the company collecting has broken the law in your case, talk to an attorney to find out how to bring legal claims against the payday lender.
Even if you are not interested in bringing claims, you should report this company to the state attorney general's office by filling out a complaint form here: http://ncdoj.gov/getdoc/fdbee1c7-c2a9-4f67-91b2-bb50beea1c0a/2-2-12-File-a-Complaint.aspx.
(The attorney responding is licensed only in the state of North Carolina. This response does NOT constitute legal advice and does NOT create an attorney/ client relationship! Rather, the response is in the form of legal education and is intended to provide general information about the matter in question. Although a response is provided to the specific question, there may be other facts and law relevant to the issue that the questioner has left out and which would make the reply unsuitable. Therefore, the questioner should not base any decision on the answer, but should confer with an attorney in person about the specifics of his or her case.)
If it was really an attorney's office, then the attorney violated the Fair Debt Collection Practices Act and ethics by threatening criminal actions (and lying) to collect. My guess is that if you Google the phone number, you will discover that not only was it not an attorney, but is also came from overseas. If you can find out who did it and that person is in the U.S., contact a lawyer to sue.
[This communication is intended as general information and not specific legal advice, and this communication does not create an attorney-client relationship.]