This document proposes changes to the sales return process of Mobilink Infinity to reduce fake sales of customer premise equipment. It describes the current multi-department process and challenges, including increasing fake sales and revenue loss. The proposal is to require customers returning equipment within the trial period to visit a customer care center, which would provide direct feedback and reduce human resource needs. This new process, inter-department coordination, and business requirements are outlined in detail. Analysis of the new process and potential benefits are also discussed, such as reducing fake sales by 80% and increasing the retention rate.