What should I do if the second-hand excavator is cheated by 654.38+ million?

If you are cheated by 6,543,800 yuan, you must first call the police. At the same time, contact the local industrial and commercial bureau or consumer association as soon as possible, or ask a lawyer to help safeguard their legitimate rights and interests. You can complain about trading platforms or businesses online, and post your experience of being cheated on your own website to remind others to shop carefully. If you can get some evidence back, you can sue for rights protection. But at the same time, we should also remind everyone that we should be cautious when buying second-hand construction machinery. It is recommended to apply for testing before purchase to avoid infringement.