As image licensing at Picfair happens in one direct transaction as soon as an image is purchased, it's unfortunately not possible to reverse the order.
To give you some more information on this process, when a digital download is ordered, a licence is immediately created, sent to the buyer with the chosen image(s) and the photographer is notified of the sale. As we are an open platform for photographers to sell their images, once an order is placed, it's impossible to "take back" the funds from the photographer - this would go against our Contributor Agreements with the artists on the platform.
If you've made a duplicate digital download order, please contact us and we'll look into this for you.