pay something back/return something with interest
return it with interest
To punish or retaliate against someone with an action that is more harmful or negative than what they did originally. After she found out he broke her computer, she returned it with interest by smashing his computer, TV, and video game console
pay something back/return something with ˈinterestreact to the harm somebody has done to you by doing something even worse to them: Peter pushed his sister, so she paid him back with interest by kicking him hard.
Interest is the extra money you receive or pay when you lend or borrow money.