You can explain it to the court. If your credit card is overdue, your mobile phone number has been changed, and you have received a court summons, you can explain to the court that a credit card, also called a credit card, is a credit certificate issued by a commercial bank or credit card company to consumers with qualified credit. It takes the form of a card with the card-issuing bank name, validity period, number, cardholder name, etc. printed on the front.