1. First of all, if the goods we purchased have completed the transaction, we can find our Dangdang online transaction order and complain directly to the merchant. There is an option to complain to the merchant on the order. As long as we fill in the reason for the complaint, After submitting it, we have completed the complaint against the merchant. After that, the merchant will pay a return visit to ask the reason for the complaint and help us solve the problem. If we think that our rights and interests have not been properly protected, we can continue to complain and go to the Industrial and Commercial Bureau 12315 to complain. 2. 12315 complaint channel: You can call the 12315 consumer complaint hotline, or go to the national 12315 Internet platform: I want to make a complaint - fill in the complaining unit - fill in the consumer information - fill in the business information, and the complaint is completed. (Let me mention here that the 12315 Internet Complaint Platform can make complaints on the WeChat official account (National 12315 Internet Platform), WeChat Mini Program (12315), and mobile app (National 12315 Internet Platform). 3. Black Cat Complaint App: Black The Mao Complaint app is a consumer service platform. No matter what platform we purchase goods on or what software we use, etc., when our rights and interests are infringed, we can choose to lodge a complaint on the Black Cat Complaint platform.