What should I do if I meet a liar who comes to work to sell physiotherapy instruments? I was cheated.

According to the relevant information, you should call the police immediately. Article 266 of the Criminal Law of People's Republic of China (PRC): whoever defrauds public or private property in a relatively large amount shall be sentenced to fixed-term imprisonment of not more than three years, criminal detention or public surveillance, and shall also or only be fined; If the amount is huge or there are other serious circumstances, he shall be sentenced to fixed-term imprisonment of not less than three years but not more than ten years and shall also be fined; If the amount is especially huge or there are other especially serious circumstances, he shall be sentenced to fixed-term imprisonment of not less than 10 years or life imprisonment, and shall also be fined or confiscated. Where there are other provisions in this Law, such provisions shall prevail. I suggest you go to your local official website for first-hand authoritative information.