It's none of your business if the former owner doesn't return the credit card, the bank calls every day, and even the bank wants to report to the police for filing a case, because the business run by the former owner has nothing to do with you, and it's none of your business to report to the police for prosecution.

Precautions for purchasing mobile phone number:

At present, the telephone number in China is completely registered by real name. You must combine your ID card with your number. You are the owner of the phone number. This needs attention.

At present, mobile phone transfer can only be done if both parties go to the operator's self-operated business hall, which can be more reliable.

Pay attention when buying mobile phone nicknames. Some nicknames have consumer protection, so do this. Many "reputations" of the three major operators have a minimum consumption guarantee. Even if they don't, they may be forcibly superimposed with a minimum consumption when transferring. Therefore, we must pay attention to this and avoid the situation that "you can afford a horse, but you can't afford a saddle".