Actually, in the US stores they take an imprint of your credit card when you waitlist for an item.
I don't think this is the case in all stores. For example I used to have to give my CC #, now they just call me and I go over to pick things up. But they don't have my number on file and they don't have an imprint, I think it depends how well you know your SA and how big the store is, etc. You are in NYC restricter? Perhaps since your store is so large that is why they do that. I think each store has their own policy, but regardless, you were are not at fault here and they should take your info now and place you back at the top of the list. Karman had good advice, I would ask to speak with a manager if your SA cannot help you.