Items in stock, then on processing they are not. Where is my REFUND!

Really? So I purchase items, when I add them to my cart, they are all in stock. My money is deducted and I am promised delivery in a week's time. Today is delivery, this morning I receive an email stating that my order is processed but with half the things I paid for?! Why have you said my items were all in stock but now I am getting half of the things, yet the full amount of money was deducted??? When is my money going to be reversed? If these products were gifts how embarrassing would it be for them to receive half their items? I need my money refunded immediately!