I experienced the exact same issue, and Support is just advising me that they are "only able to provide one code" and "you can only use the code once" even though I have demonstrated that I haven't placed an order. Feeling very let down.
I still have had problems getting mine, how do I contact them? Why is there no e-mail that I can send an e-mail to? What sort**bleep** company doesn't have a single phone number or e-mail I can contact. I have to rely on a forumthread?
Well I finally got an email saying that I would receive mine tomorrow.... remember that I ordered mine on April 11th! It's being shipped from Mississauga.... MORE THAN A MONTH after I received the confirmation! At this point I don't really care anymore & whatever "good will" Spotify THOUGHT they were going to get from this free thing - Well that ship has sailed & sunk... Meh