Not equal is the good response and the bad response. You shall resort to the nicest possible response. Thus, the one who used to be your enemy, may become your best friend.
وَلا تَستَوِى الحَسَنَةُ وَلَا السَّيِّئَةُ ادفَع بِالَّتى هِىَ أَحسَنُ فَإِذَا الَّذى بَينَكَ وَبَينَهُ عَدٰوَةٌ كَأَنَّهُ وَلِىٌّ حَميمٌ
wa laa tastawil hasanatu wa las saiyi’ah; idfa’ billatee hiya ahsanu fa’izal lazee bainaka wa bainahoo ‘adaawatun ka’annahoo waliyun hameem