Only half of my order received

Takealot notified me that my purchased products were being shipped. On delivery only one of the two items was there. The courier insisted that he only had the one item for me, and that somebody else already signed for the item he was delivering to me. I immediately raised a ticket that my order was incomplete to which they rep**** that they will escalate it to the courier company. A few hours later I received a mail confirming that shipment has been made and complete. So now I am not receiving my item that I purchased because somewhere between takealot and their courier they lost/stole my parcel? Is this the way that they do business? I did not sign for the parcels so how can they confirm the order as complete?