What a great way to calm down an angry person. Apologize for your mistakes. Make your apology and mean it, without any “buts” in your sentence. Do not make excuses. Learn to apologize sincerely. Apologize even to the child that you just took for granted.
If after your apology the person still complains and wants to talk, just listen or apologize again. But never ever say, “but I already apologized”. Because that simply confirms your insincerity.
Apology is a great exercise in humility. It is difficult to apologize when you are vain. An apology shreds vanity. An apology helps you “own” your mistakes. An apology helps you learn from your mistakes.
Do you think that an apology, a confession or repentance will automatically lead you to forgiveness? You can internally feel sorry, repent or feel total remorse for your thoughts, words, or deeds but unless you atone or externalize this to the one you have offended, deprived, insulted or cheated, who are you fooling?
What if none of those who were offended or violated are around or to be found? Then make your amends by being kind to humanity or to the universe in their honor. There must always be ACCOUNTABILITY.