will not download

That is a problem that happens when you try to download GTA V game and the online game packs at the same time. To solve this you should delete the game and clear you console cache three times:

support.xbox.com/.../clear-system-cache

Download only the main game of GTA V and play the game normally for a while. After you can download the game packs.

Hey there! There is actually an active service alert for downloading games on demand from the marketplace. All you can do is wait for the situation to be resolved.

HTTPS://www.xbox.com/status

yes as long as you are signed into the account that bought it you can re download as many times as you want for free.

Hi there, the only thing I can think of is did you ever go through your hard drive to see if there was a partial download of the game, possibly with a yellow triangle signalling that it's corrupted?

Sometimes these corrupted partial downloads can stop it from being re-download successfully the second time. See the link for more information on deleting games from your hard drive:

support.xbox.com/.../install-play-delete-game

If you can post the error code that will help, but also note there is currently a service alert related to purchasing https://support.xbox.com/en-US/xbox-live-status?xr=shellnav