それでは一旦Cを注文から外してそれ以外の3点で請求をお願いします。Cは次回あらためて注文します。ちなみにCはあなたの手元へはいつ頃届きますか?
OK, then, I'd like to cancel C for now. Please send me the invoice for the rest (i.e., 3 items).
I will place an order for C later. How soon do you think you'll get C in stock?