I bought mine at a different store but I got a mail 5 min later. The mail told me how to download and activate the products and contained 3 keys (in my case it was a bundle with EZD2 + 2EZX on own choice).
You should get a mail with a key for an expansion pack. After that you have to open up the “Toontrack Product Manager”, choose “Register New Product”, paste in the key and then you should be able to choose an expansion pack.
