I was able to find a customer service phone # (NOT easy) 415-800-5959 and the rep was extremely helpful. She could tell that the gc I sent had not been redeemed (luckily it was a very unusual email address even in my error, and thus no one had the address I had entered so no one had received the notification email of the gc. She was able to cancel the outstanding gc so that I could resend it correctly. Super helpful once I found her. Hopefully they will add an FAQ for this question because surely we can't be the only two to make this mistake! Good luck. If the email address you entered by accident is remotely common, act fast...