Contact the bank promptly to provide evidence and understand relevant regulations.

1. Contact the bank promptly: Contact Bank of Communications immediately to explain the violation and request the bank to handle it.

2. Provide evidence: Relevant evidence, transaction records, receipts, etc. should be provided to the bank to prove the violation.

3. Understand the relevant regulations: You should understand the regulations and related policies for the use of Bank of Communications credit cards in order to better comply with the regulations and avoid violations.