Accidently purchased kit twice?

Sorry I know this is in the wrong spot, but I don't know who to contact?
I just purchased the book Nook Kit and didn't see it come up in my Library or get any confirmations so I bought it again thinking I did it wrong the first time. But now it's come through for both times.
I'm stressing out, does anyone know who I contact for a refund on one of them?