How can we be sure it's fake? Who is sure? It's useless for ordinary people to be sure. If you really want to go to court, you must have a test report issued by the state to be effective, otherwise it will be invalid. If it is confirmed to be false, then spend some money to get a report first, and then take all the vouchers such as the shopping receipt to the store, or you can directly sue. If everything is finished, you win, otherwise it's hard to say.