If the creditor fails to repay the arrears and loses contact, the creditor can take the following measures to safeguard its legitimate rights and interests:
 1. Apply for property preservation before litigation. First file the property preservation before litigation to the court, and seal up the debtor's property to prepare for the future implementation phase
 2. Go to the court to sue for repayment. If the other party still cannot find the person who owes money, the court can accept if there is a clear defendant, residential address and contact information. After filing a case, the court usually summons the debtor to answer the lawsuit in the form of public notice service. When the public announcement period expires and the debtor does not respond to the lawsuit, the court will make a default judgment on the case with clear relationship between the borrower and the debtor after hearing.
 3. Apply to the court to declare the debtor as missing person. If the property custodian of the missing person refuses to pay for the loss, the creditor shall bring a lawsuit, and the people's court shall list the custodian as the defendant.
 4. Try to find out who is responsible for joint repayment or joint repayment of debts.
 [Legal Basis]
 In Article 92 of the Civil Procedure Law, if the whereabouts of the person on whom the service is to be made is unknown, or if the service cannot be made by other means specified in this Section, the service shall be made by public announcement. Sixty days from the date of the public announcement, it shall be deemed to have been served.
 In case of service by public announcement, the reasons and process shall be recorded in the case file.