楽しみにお待ちいただいていたのに、嫌な思いをさせて申し訳ありません。
そのitamは確かに2つ購入いただいています。
こちらのミスで1つだけ発送してしまったと思われます。
大至急追加で発送いたしますがお待ちいただけますか?
I am very sorry for making you feel bad even though you were looking forward to it.
You certainly purchased two of that item.
We consider that because our mistake only one was sent.
We will send the other one as soon as possible, could you wait for it?