The account has been frozen. You can try to find customer service of the bank card itself. Which bank does this bank card belong to? Although you will know when you apply for a bank card, ask them how long the customer service bank card has been frozen and why. Whoever grants the right, the bank itself does not mean that whoever wants to freeze the bank card must be authorized by the law enforcement department, which is the case in our country and abroad. Of course, law enforcement agencies in China must have this right, and there may be differences abroad because of different administrative systems.
If your bank card is frozen for a short period of time to 24 hours or 48 hours, it proves that you have only made a small risk transaction, which does not involve long-term freezing. Don't do anything, just wait, and your card will be basically unsealed after 48 hours. Because this short-term freeze may be automatically detected by the banking system, so don't think so much. It may freeze for a long time if you make it yourself. If it is the kind that has been frozen for a long time, reaching half a year or even a year, then you have to do something.
Because in China, the freezing time of bank cards is generally half a year, not to say that there is no such thing as 24 hours and 48 hours, but that there is no such thing as a long term, and there is no such thing as a month or two. Basically, the first half of the year involved transnational crime, economic fraud and so on. If it is a special area, such as Beijing, it may be frozen for one year, which is more risky and stricter, so the freezing time will be longer. Don't worry about whether the money is particularly small, and don't use this account if there is too much money. If you have a lot of money, you can try to find some law firms to help you solve this problem.