* On the email telling you about your item, click "Track your Package"
* On the bottom of the page that comes up, in Amazon's website, click "Help"
* On next page, click "Need More Help" and "Contact Us"
* then " 2. Select an issue" and in the box find and click "where's my stuff?"
* underneath that "Talk with us" and you give them your phone number and they'll call back immediately. Probably will say heavy call volume so you can instead click "chat", which is probably better given the language barrier you'll probably encounter with the rep.
If it's a 3rd party seller, like Adorama, they'll contact Adorama and then call you back to say whether they've agreed to send you a new version of the item. They also took a new delivery address so the next time it wouldn't get stolen.