According to the registered signal in the short message, you can call the postal service hotline to check the mailing progress, such as where to send it, whether it is the local post office, whether it has been delivered, whether it has been signed for, etc. Or have you already returned it? If you have signed for it, you can confirm the signing place, such as unit doorman and community security. After you know it, you can go to relevant places for further search; If there is no signature, return it to the bank. You can contact the bank to check the address and ask for a new mailing arrangement.