Unacceptable delivery service

I paid for my order to be delivered the next day, come the next day( today) no order has been received. In the ordering process the item was in stock and in JHB warehouse, therefore I placed it and selected the option to deliver the next day and paid the price. Now I have to wait until Monday after weekend 3 days later for it to be delivered. It is unacceptable especially if the item was in stock and I am based in the area.