You can complain to Douyin officials if a Douyin merchant violates the rules. Douyin has a dedicated customer service team that handles merchant complaints. Once a merchant finds that their rights have been violated, they can complain to the official customer service through Douyin's official website or APP.

On Douyin, merchants can report violations through the reporting system. Once verified as violations, Douyin officials will take corresponding measures to deal with them. In addition, Douyin also provides a "User Rights Protection" module, in which merchants can submit complaint information and related evidence so that Douyin officials can review and handle the complaint.

In short, if you encounter a merchant violating the rules on Douyin, you can complain to Douyin officials through official channels.