If you live anywhere near a Pay Point outlet, you can get another fiver off the download code by topping up £20 in-shop:
Get a £5 promotional credit added to your Amazon.co.uk account when you Top Up in store £20 or more in a single order (the "Offer")
Top Up orders online at Amazon.co.uk are excluded from this Offer.
Amazon Top Up – In Store transaction must occur between 12:01 am (BST) on August 15, 2017 and 11:59 pm (BST) October 31, 2017.
The promotional credit must be redeemed on Amazon.co.uk, towards the purchase of products listed on and sold by Amazon.co.uk. Promotions & Deals Terms & Conditions apply.
Offer limited to one per customer and account.
The maximum benefit you may receive from this Offer is £5 off products sold by Amazon.co.uk.
You will receive an e-mail from Amazon within 1 hour that indicates the amount of the promotional credit that has been applied to your Amazon.co.uk Gift Card Account.
The promotional credit expires at 11:59 pm (GMT) November 30, 2017.
Amazon reserves the right to modify or cancel the Offer at any time. The promotional credit may not be combined with any other promotional offer.