when there is an error in the statement or there are more consumer accounts that you don't recognize, the possible situations are: negligence of the special merchants, negligence of bank operations, fraudulent use or forgery of the credit card, or your own forgetting.

you should immediately notify the issuing bank by telephone or in writing, and indicate your name, account number, type of error, date, amount and data evidence. The issuing bank will investigate and correct any errors; There is no mistake, and the reason will be explained to you. During the investigation, you don't have to pay the disputed amount.

if the card is lost and used fraudulently, as long as you complete the reporting procedures within the time specified by the issuing bank, all the losses incurred will be borne by the issuing bank.

in case you forget to have this expense yourself and ask the card-issuing bank to read and sign the bill, some card-issuing banks will ask you to pay the fee for reading and signing the bill, and the fees vary. So you'd better think again to see if you forgot this consumption, and then ask the issuing bank to investigate. Therefore, after each consumption, you should at least keep the signed bill until the next month's statement comes, and then destroy it after checking it. This is very useful.