When are people more likely to make complaints?

People are more likely to make complaints when they feel that what they received was clearly below what they were promised, especially if money, time, or respect is involved. For example, if a product is faulty, a delivery is very late, or a staff member is rude, customers usually feel they have a reasonable reason to speak up. I think written complaints are better for serious problems because there is a record of what happened, but talking face to face can be more effective if the issue is simple and needs to be fixed immediately. If I received poor service at a restaurant, I would probably stay calm and explain the problem politely, such as saying that the food was cold or the order was wrong. I would not make a scene unless the staff completely ignored me. In general, people respond to poor customer service in different ways: some complain directly, some leave a bad review online, and others simply never return. In Vietnam, people often complain about slow service, delayed deliveries, poor product quality, and sometimes unclear pricing or unhelpful staff. I would say younger people complain more openly, especially online, because they are more used to using social media and review platforms. Older people may complain too, but they sometimes prefer to tolerate the problem or speak privately. Of course, some individuals complain more than others because they have higher standards or a more direct personality. For companies, dealing with complaints is extremely important because complaints reveal weaknesses in the service. Even children can learn how to complain in a reasonable way, for instance by explaining what is wrong instead of just crying or getting angry.