Incorrect order and more waiting

I recently purchased an SSHD from takealot (order ***). However, the incorrect item was delivered (RRN: RRN-5564-8b3a). I've been told that there is no stock available and that I could either wait or be refunded.<br> <br> However, I am able to add the item to the cart so I don't understand why there is a wait. Moreover, if I was sent the incorrect item by mistake, how could the stock have been depleted? It's very disappointing to receive the incorrect item and then to be offered inconvenient solutions. What's going on?