You can mouse over your account avatar, where a drop-down menu will appear. Go to the one that says "Orders and Settings". You should see your order there and a green shield next to it. Upon mousing over the icon, you shall see it's the money-back guarantee (if you qualify, which you should if your purchase is recent). Next to it is an arrow. Click on it, and there is the "Contact Support" button.
Because doing it by this way nets a more direct line, as your order number is automatically included in the query.