Gamestop sucks! I got taken by this deal as well. Guess I didn't know their "while supplies last" works differently than other companies. I assumed that if they ran out of codes, that you would not be able to complete the purchase. Wrong! It is a total crap shoot on whether you will receive...
Amazon has the Firefly series on bluray for $31.99 shipped.
http://www.amazon.com/Firefly-Complete-Blu-ray-Nathan-Fillion/dp/B001EN71CW/ref=wl_it_dp_o?ie=UTF8&coliid=I2PX6MCM5N1T78&colid=2DIGKYSDNU4QW
Trustworthy, not a hassle...just takes a little time to do the surveys. I have received about $200 in Gamestop gift cards over the last two years. Would definitely recommend.
This is the best deal I have seen on this tv series. I have been wanting it for a while but did not want to pay $69.99 for it. It finally reached my price point. Hope it helps someone else.
Sorry I posted before finishing. The deal is through Amazon...