What is the ruling of the Sharia regarding filing a complaint against three neighbors accused of stealing a phone valued at 325 dinars, especially since the questioner's brother had his phone stolen twice before?

A Muslim must avoid ill thoughts of others, especially neighbors, as accusing them of theft based solely on suspicion is forbidden and a violation of their honor. If you are certain that one of them has stolen or has a history of such acts, you can advise them and warn them of God's punishment. You are not permitted to report them to the judiciary without lawful evidence, but you can inform the security authorities. If the thief is your brother, this negates the accusation against the neighbors.