According to the provisions of the Auction Law and the Guarantee Law, the original owner of a car auctioned by mortgage law has the obligation to assist in handling the formalities of car sale, and it is illegal not to assist. When dealing with this situation, you can contact the relevant auction institutions or auction companies, reflect to them the situation that the original owner did not assist, and provide relevant evidence. You can consult a lawyer to learn about legal channels and solutions. According to the specific circumstances, it is necessary to investigate the responsibility of the original owner through legal procedures to ensure that the legitimate rights and interests are protected.