All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The oppressed has three options with the person who had oppressed him:
1- Pardoning the oppressor out of seeking the great reward that Allaah has promised. Allaah Says (what means): {And whoever is patient and forgives — indeed, that is of the matters [requiring] determination.}[Quran 42:43]
2- Not pardoning the oppressor and reserving one’s right so that the oppressor would face the punishment of Allaah sooner or later.
3- Taking one’s right and returning an evil with an evil without excess. Allaah Says (what means): {And whoever avenges himself after having been wronged — those have not upon them any cause [for blame].}[Quran 42:41]
The best of these three options is the first option as long as it is not feared that it would lead to a greater evil.
Finally, it should be noted that resorting to man-made laws is not permissible except in case of necessity. For more benefit, please refer to Fatwa 89824.
Allaah Knows best.