Article 196 of the Contract Law stipulates that a loan contract is a contract in which the borrower borrows money from the lender and returns the loan and pays interest when due. Article 206 stipulates that the borrower shall repay the loan within the agreed time limit. Article 207 stipulates that if the borrower fails to repay the loan within the agreed time limit, it shall pay overdue interest as agreed. According to the above legal provisions, the relationship between you and the bank is a loan contract. If you are overdue in repayment, the bank has the right to send a lawyer's letter to demand payment. But you don’t have to worry, this is a common civil dispute. It is recommended that you go to the bank where you originally applied for the credit card immediately, explain the reason for the overdue repayment, and then apply for a replacement for the lost credit card. Just pay the outstanding amount through the bank counter.