Ephesians 4:26-32 is a good reference if you’re holding on to an issue that died out a long time ago. Slander is not the answer. Find peace in the Word.
 Be angry, and sin not. Let not the sun go down upon your anger.  Give not place to the devil.  He that stole, let him now steal no more; but rather let him labour, working with his hands the thing which is good, that he may have something to give to him that suffereth need.Let no evil speech proceed from your mouth; but that which is good, to the edification of faith, that it may administer grace to the hearers. And grieve not the holy Spirit of God: whereby you are sealed unto the day of redemption.
Let all bitterness, and anger, and indignation, and clamour, and blasphemy, be put away from you, with all malice. And be ye kind one to another; merciful, forgiving one another, even as God hath forgiven you in Christ.
Sometimes it’s hard to let go of a dead issue. Holding on to an accusation in which you have been proven incorrect by documentation is damaging to the soul. I pray you find peace.