Can't redeem loot card

I hope I can get some help with this. I have tried to redeem a UD loot card for Landro's pet box, and the code isn't valid.

Yes I know how to do this - this will be pet box number nine for me - the first 8 worked fine. I have the blizzard code, but everytime I give it to Landro, it comes back as an invalid code.

I tried renaming my cache, interface and WTF files and going that route. Didn't work.

I turned off all my add ons. Didn't work.

I have spoken with Upper Deck twice, e-mailed them twice. Each time they tell me it's a Blizzard problem.

I took a ticket out with Blizz - they say it's a problem with UD - not them.

Besides giving up on buying trading cards, what do I do now? Blizzard will not give me a new code, UD won't touch it - I want my stupid pet box!