30D is a "sister size" to 32CYeah they should take them at the American Eagle stores but you can always call and see. It's usually free shipping on 50 tho and that takes about a week. Yeah you should its a great price so its not like you're losing. I usually give my bras away if they dont fit unless i paid a grip for em. Hmmm im not sure about a 30 D tho.
For example, I know with VS swimwear that is sized like bras, I need to go to a 34B because for some reason the 32C is too small.