@SianThole
No, I'm afraid you can't as you are limited to where you rented it which is your mobile. As you want to watch this via your Sky box then you needed to have rented it via it.
As you will now be charged for it all I suggest you do is to use the live chat to the Sky Store team tomorrow to see if they can help. You can access it from 11am-7.30pm Monday to Saturday and can be found here:
https://www.skystore.com/help/contact-us
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