First of all, banks must aim at making profits. The bank negotiates that your credit card will only repay the principal, so that you can repay the money owed to the bank as soon as possible. If the bank agrees not to pay interest when you repay the principal, it is often a scam. Because according to the relevant policies, you still need to pay back the money. At that time, you didn't pay off the interest and the principal together, so you still owe money, and you will definitely continue to increase the interest and liquidated damages. Selling cards doesn't mean selling them right away. Generally, after a settlement period, it takes about 40 to 50 days to confirm that the account is no longer used, and then the account can be closed, because sometimes the refund of the merchant will automatically return to the original card number.