This is a 3rd conditional sentence which relates to the past. Someone experienced an unpleasant action, and the speaker is commenting on the action. There are 2 events in the time line. --------------------------------PAST-------------------------------------------------------------------------------NOW ---- (1) unpleasant experience --------->(2) not allowed such behaviour----------> Hypothetically: It was possible that someone would try to be unpleasant to the speaker(in the past). !(1) In that event, the speaker would not allow such action (2) If clause + past perfect (further past) + would + present perfect (resulting action clause)

The English is perhaps not the best, but I can attempt it. It sounds like a situation where someone (A) tried to do something (x) to another person (B). Person (C) is commenting on it, and saying that if person (A) had tried to do the same (x) to them (Person C), that they (Person C) would not have permitted it (x) to happen. (Whatever IT(x) is).