fight back, retaliate, hit back, respond, react, reply, reciprocate, counterattack, return fire, return the compliment, put up a fight, take the bait, rise to the bait, return like for like, get back at someone, get, give tit for tat, give as good as one gets, let someone see how it feels, give someone a dose/taste of their own medicine;

have/get/take one's revenge, take/exact/wreak revenge, be revenged, revenge oneself, avenge oneself, take reprisals, get even, even the score, settle a/the score, settle accounts, pay someone back (in their own coin), pay someone out, repay someone, exact retribution, take an eye for an eye (and a tooth for a tooth)

informal give someone their comeuppance

British informal get one's own back

rare give someone a Roland for an Oliver