Cardholders can unfreeze their cards by calling the customer service hotline of China Merchants Bank or going to any offline business outlet of China Merchants Bank. If your credit card is frozen because it is overdue, you need to pay off the balance first and then handle the unfreezing process. If the bank suspects that you have cashed out and it is frozen, the cardholder needs to bring the relevant consumption certificate to the branch to unfreeze it.