DKEVINZ is correct. Just last night, a friend finally found the insert he received with the BF2 game I bought him for Christmas and messaged me with the original turn-in code. I was able to redeem it successfully. That, in turn, provided me with a shareable link, which says:
SPECIAL FORCES ARMOR SET*
Custom crafted for the most elite soldiers in the galaxy!
Expires: March 31, 2018
Redemptions Remaining: 3
Which encourages you to share with your friends, as those 3 people will get and can share with 3 more, etc.
I gave this link, just moments ago, to a friend of mine who had also missed the promotion (as a side note to that, I received no email, nor were there any tweets about the SPECIALFORCES promotion back in November which is sort of sadness since I don't read the SWTOR news pages or forums much, but I digress). The message she received back was that code was no longer valid, yet I still show 3 uses and I have not given it to anyone but her.
So, please can we get this fixed prior to the March deadline?