Online Order - Half of the order delivered !!!

On Saturday 26 Jan 2019 I ordered online only deal of 2 medium pizza's tikka & something meaty, 1 death by chocolate + 1 1L coke at Debonairs Eldoraigne for delivery, order number: 83 Invoice number: 777312 at 18:21. I was far from home and the order was for my kids. I told my kids what I ordered and when the driver arrived at the gate he ONLY gave them 2 medium pizzas. My eldest son then phoned me to tell me they didn't get the rest of the order and when he asked the driver he said the order was for two pizza's only!! I tried to chat live to Debonairs and I didnt get any assistance from the chat. My question is What happened to the rest of my ORDER!! This is *****/******** of customers. Not sure if its the driver or the said store's fault but I demand my money back!