1. Contact the customer service department of the bank: you can call the customer service hotline of the bank or go directly to the counter of the bank for consultation, explain the problems encountered and ask for help.

2. Submit a written complaint: If you think that the bank failed to solve the problem in time and effectively, you can prepare a written complaint and send it to the relevant department of the bank.

3. Seek third-party mediation: If the above methods fail to solve the problem, you can consider mediation or litigation through third-party institutions such as courts and arbitration institutions.