Well the post you linked to says they expired on the 02/03/13, and yeah, they're gone.
[LIVE] Borderlands 2 SHIFT Codes (02/01/13)
Released 02/01/13, dunno when they expire.
They may have expired, post results.
THE EYE OF AN ADMINISTRATOR IS UPON YOU. ANY WRONG YOU DO IM GONNA SEE, WHEN YOU'RE ON MPGH, LOOK BEHIND YOU, 'CAUSE THATS WHERE IM GONNA BE
"First they ignore you. Then they laugh at you. Then they fight you. Then you lose.” - Dave84311
HAVING VIRTUAL DETOX
Well the post you linked to says they expired on the 02/03/13, and yeah, they're gone.