why do netflix charges me for a movie rental on apple tv ?

That doesn't make any sense. Where are you renting this movie from? You can rent from "You Tube" "Hulu" "iTunes"? What channel are you renting from?

vazandrew is right. Netflix doesn't rent movies, they stream for $7.99 a month. $5.99 sounds like an iTunes charge. You need to check the account these charges are made to, and make sure you know who's charging you what and when.

Netflix doesn't rent movies. You are renting through iTunes. Netflix charges 7.99 per month for a streaming subscription service. If you have a billing issue then contact Netflix.