Just buy a 60 day FFXIV gamecard or a $20 PSN card and you should receive instantly you dlc code on your e-mail registered with them.
If by any chance you still don't receive your code you can contact them through live chat (not e-mail) and they should give it to you right away!
Just make sure your order for dlc code on the order summary before placing your order.
But hurry up because promtion ends next Monday.