$10,000 is a lot of money. Based on your facts, I suspect that having an attorney respond to the demand, essentially telling them to pound sand and also providing some reasons why the money is not owed will help to get this resolved quickly. You can schedule a free case assessment 24/7 by calling 303-688-0944 or online at /locations. At your appointment, we'll meet by phone or video (Zoom), we'll discuss your contract, the current demands and contact with your new employer, desired results, rights, remedies, the law, the process, timeline, how we can help, costs, etc