Thank you for the information and your question. Although it is doubtful, based on the few facts that you have provided, that this would be a criminal harassment case, you might definitely have a cause of action for defamation
of character. If these people made false statements of fact about you to a third party, and this has damaged your reputation, then that would be defamatory. In that case, you will want to sit down with a local trial/litigation
attorney who handles non-physical injury torts
(which is what defamation of character is) and discuss all the details with them to see if they think your case is worth filing, or whether a "cease and desist" letter should be sent first as a warning not to continue with this behavior.
You can see the ND harassment statute at the link below, but it requires telephone or written threats, so if those did not occur, this would not be an option. If you do have information that would meet the statutory requirements, then you can file a police report against them. The the prosecutor would be the one to decide whether or not to pursue charges.
Please let me know if you need any clarification. I would be glad to assist you further if I can.