Hi Pabliki,
If your download is interrupted because you are leaving the Wi-Fi network, you can resume the download at another time. Once the movie rental is downloaded, you will have 30 days to watch it. Here is some information regarding movie rentals, resuming downloads, and contacting iTunes Store Support regarding purchases:
https://support.apple.com/en-us/HT201611
https://support.apple.com/en-ca/HT204312
https://support.apple.com/en-us/HT204088
The steps below show you how to check your purchase history to see when your account was charged for a purchase. If you're looking for more information on what you bought or need help with a purchase, try these steps:
Take care,