Redemption codes on PS3 games

So I just need to vent. I got Killzone 3 earlier this year as a gift. It is the Helgast edition which came with a redemption code. The code had expired the day before I opened it. I know my wife bought it a couple of months before she gave it to me. I don’t understand why these codes expire. I wonder how much money game buyers lose to this every year. I contacted Sony and they just said sorry for the inconvenience.

I need to partially retract this gripe. After a few emails and a couple of months Sony did add the download content that this code was code for to my account. I am downloading it now. So the bottom line is Sony did come through, it just took awhile. Still not sure why these expire. I suppose maybe they take the content offline.