It may not be easy to leave things "unresolved". Someone can attempt to attack your character or attempt to devalue you in many ways, but it is your job to recognize the attempt and disengage. Take the high road, as often mentioned. You do not have to interact with the one who seems to want to unravel you. This can make you feel as if you are leaving things unresolved, but really you are giving yourself peace of mind. A fool will only perform with an audience. Don't provide them with your time and the fool will remain a fool. Take the high road and gain peace.