Sadly, there's a type of people that will keep coming back to you as long as you reply. They won't accept what you are telling them, they will endlessly keep rephrasing what they want from you, coming up with endless explanations how it's very bad of you to not do what they are requesting. And once your patience finally runs out after 20 emails back and forth, they will throw a massive tantrum, that sometimes includes false complaints, reviews, and takedown requests. Ignoring them in the first place saves you the trouble. I guess, they quickly pick another victim instead.