Sounds like they got all the cards at once with the shelf display, and some stores aren't aware of which ones to give out in which week.

Maybe if someone does a decent sized purchase at Target, ask for one of each of the 12 cards, saying that it prevents them from giving you the wrong one for that week. (it'd suck if they gave out an early week card in one of the later weeks, preventing you from being able to enter at all for that purchase)