Has the questioner been completely absolved of the injustice and fully reconciled with the Imam after what happened, and has he met the fourth condition for repentance, and has he cleared his conscience, and is there nothing held against him after that?

Since you have reconciled with the Imam and sought his absolution, you have fulfilled your duty. The responsibility for the estrangement now lies with him. You should remind him that it is not permissible for a Muslim to abandon his brother for more than three days. You should also advise your father, if he wronged the Imam, to seek his forgiveness and ask for his pardon.