one is allowed to take one’s revenge but to forgive is better. See what Quran says:
وَالَّذِينَ إِذَا أَصَابَهُمُ الْبَغْيُ هُمْ يَنتَصِرُونَ ﴿٣٩﴾ وَجَزَاءُ سَيِّئَةٍ سَيِّئَةٌ مِّثْلُهَا ۖ فَمَنْ عَفَا وَأَصْلَحَ فَأَجْرُهُ عَلَى اللَّهِ ۚ إِنَّهُ لَا يُحِبُّ الظَّالِمِينَ ﴿٤٠وَ لَمَنۡ صَبَرَ وَ غَفَرَ اِنَّ ذٰلِکَ لَمِنۡ عَزۡمِ الۡاُمُوۡرِ ﴿۴۳﴾﴾ وَلَمَنِ انتَصَرَ بَعْدَ ظُلْمِهِ فَأُولَٰئِكَ مَا عَلَيْهِم مِّن سَبِيلٍ
And those who take revenge only when they are oppressed; because the recompense of evil is the same evil. Then he who forgave and reformed matters, his reward rests with God. Indeed, God does not like the unjust. And take note that those who have been oppressed and they took revenge after it, then it is they who have no blame on them.
Blame is on those only who are unjust and show rebelliousness in the land without any justification. It is these people for whom there is a painful torment. However, those who show patience and forgive, then these indeed are the works that have been emphasized.42: 39-43
وَلَا تَسْتَوِي الْحَسَنَةُ وَلَا السَّيِّئَةُ ۚ ادْفَعْ بِالَّتِي هِيَ أَحْسَنُ فَإِذَا الَّذِي بَيْنَكَ وَبَيْنَهُ عَدَاوَةٌ كَأَنَّهُ وَلِيٌّ حَمِيمٌ ﴿٣٤﴾ وَمَا يُلَقَّاهَا إِلَّا الَّذِينَ صَبَرُوا وَمَا يُلَقَّاهَا إِلَّا ذُو حَظٍّ عَظِيمٍ ﴿٣٥﴾ وَإِمَّا يَنزَغَنَّكَ مِنَ الشَّيْطَانِ نَزْغٌ فَاسْتَعِذْ بِاللَّهِ ۖ إِنَّهُ هُوَ السَّمِيعُ الْعَلِيمُ
In reality, good and evil are not equal. [There is no doubt that these disbelievers of yours are now after evil, [39] but] you do that which is good in response to evil. Then you will see that the very person between who and yourself there is enmity, it is as if he has become a bosom friend. And [remember that] this wisdom is acquired only by those who are steadfast and this wisdom is given to only those who are very fortunate. And [if at some instance] you feel temptation in your heart from Satan [43] seek God’s refuge. Indeed, it is He Who hears and knows. 41: 34-36