Uploaded Items to Amazon Advantage

Yes I've finally uploaded the book to Amazon Advantage. That was fairly easy, then I received the email from Amazon asking me to post one copy to their distribution centre in Bedfordshire. I filled in all the forms and then it gave me the address where to post it. After posting you're meant to fill in one more item saying that it's been posted. But there's a problem. Only after you enter the date it was posted (which I did AFTER I'd posted it) it then gave me an address label with a compulsory bar-code which had to be on the package. So I had to print that out and send off another copy. Probably the first one won't get processed, but after having come this far I don't mind losing one copy.