I canceled a pack download and it is completely gone now why?

I got Gta 5 on my Xbox 360 and had to download a few parts first, then I accidentally canceled all updates and a file was completely lost (Part1) I can no longer download it even if I'm always in Gta back in and out, nothing works. And then I ask myself the question: how can I restore the download? Do I have to download Gta 5 again or is there another way?

If the program with which you are loading does not have an internal buffer where it puts the file in, it is gone when terminated.

So completely, it only helps to draw again.

OK thanks