After receiving the Platinum Credit Card from China Bank, what should I do with the previous card?

China Bank Credit Card Cancellation Method:

If China Bank credit card holders are unwilling to use BOC series credit cards for various reasons, please cancel your credit card to avoid automatic deduction of annual fee.

Cardholders should call the 24-hour customer service hotline to apply for account cancellation, and Bank of China will check the status of the credit card under the customer's name. If the account cancellation cannot be completed immediately, the bank will cancel the account for the customer 45 days after the cardholder applies for account cancellation and there is no debt or balance in the customer's account; If there is still debt, the bank will take the initiative to inform the customer to repay as soon as possible and complete the account cancellation; If there is any balance, you can go to the branch of China Bank to return the balance. When the main credit card of BOC is cancelled, all the subsidiary cards under its name will be cancelled.