What should i say to this?

Put your feelings aside for a moment and try and look at it from their point of view. After you've done that, do your best to clear up any misconceptions that they may have gotten from the conversation. Finally, explain your feelings on the matter. Don't be defensive, just be calm and honest. If they still insist on their position, you can agree to disagree with them. Prove that your the better person by not making the world 'an eye for an eye.'