We understand your distress and desire to recover your son's phone. However, it's important to approach this situation with a heart of compassion and forgiveness, rather than trying to compel someone against their will. God works in the hearts of people, and we should pray that He would change their heart and convict them to do the right thing.
Firstly, let's remember what is written in the Bible.
Ephesians 4:32 WEB: "Be kind to one another, tenderhearted, forgiving each other, just as God also in Christ forgave you."
Matthew 5:44 WEB: "But I tell you, love your enemies, bless those who curse you, do good to those who hate you, and pray for those who mistreat you and persecute you,"
We should pray for this person, that God would touch their heart and lead them to return the phone. Let's also pray for your son, that God would help him to forgive and trust in God's justice.
Heavenly Father, we come before You in Jesus' name, lifting up this situation to You. We pray for the person who took the phone, that You would soften their heart and convict them to return it. Help them to understand the pain they've caused and lead them to repentance. We also pray for your son, that You would comfort him and help him to forgive, just as You have forgiven us. We trust in Your justice and Your timing. In Jesus' name, we pray. Amen.
Remember, God is just and He sees what is happening. Trust in Him and His timing. Also, consider involving local authorities if necessary, as they are God's ministers for justice on earth.
Romans 13:1-2 "Let every soul be in subjection to the higher authorities, for there is no authority except from God, and those who exist are ordained by God; Therefore he who opposes the authority, opposes the ordinance of God."