First of all, the first method is to reissue the card. The easiest way to unblock an ordinary bank is to apply for a new card. The new card must be of another card type.
Second, the second is to call the credit card customer service to ask for unsealing. However, the condition of this method is that the card seal is not caused by serious overdue. Usually the application is submitted and the bank can verify the situation.
Third, the third is to provide formal invoices. If the card is blocked due to suspected cashing, the cardholder should issue a formal invoice for the small ticket suspected of cashing, and submit these materials to the bank counter. After inspection by the staff, it can usually be unsealed on the same day.
Fourth, pay off the arrears and apply for unsealing. If your card is blocked due to arrears, you can only apply for opening it after paying off the arrears in one lump sum. If not, try to coordinate the repayment plan with the bank. Sometimes, banks will allow credit cards to be unsealed in this way.