However, if the store to be returned does not make an additional return promise, there are two situations: one is that the clothes are of poor quality, and the other is that the contract can be terminated due to fraud, coercion, gross misunderstanding or obviously unfair.

You have to understand what fraud is, and it is the other party's own behavior and language that make you misunderstand. There must be a causal relationship between the two.

In other words, you clearly know that clothes have no brand, no trademark, no price tag, and the shopkeeper has not misled you into saying that they are brand-name clothes. In this way, if you two reach an agreement, even if it is expensive, it is not a revocable contract. So if there is no quality problem, it can't be returned.