It will not affect your creditworthiness, it will only affect his own creditworthiness. When your relatives apply for a credit card, they should write your name in the "Relative Contact Information" column, so the bank can find you;

You can call the customer service of Ping An Credit Card Center to ask. Customer service hotline: 95511-3 (Credit Card Center).

Or you can find out how much he owes, and then go to the counter of Ping An Bank or pay it off for him on LaKaLa's machine. After repaying the amount, you can call the Ping An Credit Card Center to request to cancel the card.