Originally Posted by Zandel

What I don't understand is why they limit these codes at all... they are 4* girls it's not like they are rare or anything. We can get them all from the normal Gacha and apart from Cepha I already have them all anyway. they should just make this like the Violet Tulip promo and allow any number of redemptions (1 per account per girl) within a certain time frame (maybe 2-3 days).

Since it was intended for new players they probably didn't expect to run out so quickly. If they have 1k codes each that's still a fair amount, but not nearly enough for the existing playerbase.