Dear Mr. Tony,
We thank you for supplying the urgently needed books by courier.
We wish to inform you that the earlier batch of books sent via lorry transport still have not arrived. We have to presume that they are missing. Perhaps you could query the transport company and see if they can recover the goods.
Meantime could you send us a c/n for the missing books? Your invoice for the said books is No.1234. If the books finally do arrive, we shall inform you immediately.