I've prepurchased a movie on appleTV but I cant see it in my purchase history and I can't play the movie

What do you mean "prepurchased"? If it was on Pre-Order, that means it has not been released yet, and you won't see it in your purchase history or your library until it is released and you are actually charged for it.

You don't get early access to it. You just set it up to be automatically purchased the moment it becomes available.

See here: link-> See or cancel pre-orders for apps, movies, music, or books - Apple Support