1. Collect relevant evidence: In order to support the claim, it is necessary to collect relevant evidence about the deduction, such as bank statements and transaction records, which will help to prove that the deduction is unauthorized.
2. Contact the bank: If Yunnan Cheng Bang Financing Guarantee Co., Ltd. refuses to refund or has other problems, you can contact the bank or credit card company to report the unauthorized deduction, and the bank will take measures to help recover the deduction.