retribution

• Give someone a dose of their own medicine

  To treat someone with the same unpleasant or unfair behavior that they have previously inflicted on others.

• A taste of your own medicine

  To experience the same unpleasant treatment or consequences that one has inflicted on others.

• give someone a taste of their own medicine

  To treat someone with the same unpleasantness or negativity that they have shown towards others.

• Payback time

  This is the moment when someone receives deserved punishment, retribution, or vengeance for a past wrong or perceived injustice.