You can get one from Amazon, but they are a bit pricey.
Portal 2: Songs To Test By https://www.amazon.com/dp/B009DJB8I2/ref=cm_sw_r_cp_api_glt_fabc_E6B66Z144GWKA00KQQSJ
You didn't pay for the tf2 item and dota 2 code. It doesn't even say anything about a TF2 code on the amazon page. You paid for the soundtrack. If you happen to get the TF2 code, that's a bonus. If I ordered a pizza and got a free order of breadsticks when it was delivered to me, that would be a bonus. If I only ordered the pizza, and just received the pizza when it was delivered, I wouldn't be upset because that's all I ordered.
items_game.txt DID update, but my guess is that it's for the styles on the Crafty Hair. I'll edit once the file has actually downloaded.
Edit: There is something interesting...
! "name" "Portal 2 Soundtrack Promo Package"
! "item_class" "craft_item"
! "craft_material_type" ""
! "show_in_armory" "0"
! "image_inventory" "backpack/crafting/gift_mystery"
! "image_inventory_size_w" "128"
! "image_inventory_size_h" "82"
! "item_quality" "unique"
! "propername" "0"
! "min_ilevel" "1"
! "max_ilevel" "1"
! "item_type_name" "#TF_Package_Type"
! "item_name" "#TF_Portal2_Soundtrack_Promo_Package"
! "item_description" "#TF_Portal2_Soundtrack_Promo_Package_Desc"
! "mouse_pressed_sound" "ui/item_paper_pickup.wav"
! "drop_sound" "ui/item_paper_pickup.wav"
Portal 2 Collector's Edition Soundtrack is set to be released on October 30th - http://www.joystiq.com/2012/09/24/portal-2-songs-to-test-by-collectors-edition-out-on-october-3/
Buy it on Amazon - $17.81 USD
X-Com items are also tradable.
Btw, Amazon has the collector's edition for only $18.