Games : I just bought TF2 as part of the Valve Complete Pack. Where's my Proof of Purchase helmet?

I bought a Valve Complete Pack license off an external site (Here, to be exact), which came with TF2 (which I hadn't downloaded before).

I'm pretty sure I have a premium account because my backpack has a lot of "pages", but I don't have that Proof of Purchase helmet that I understand I'm supposed to get. Is some extra step required? Or would I have had to buy the game from Steam, not just activate it there?