Late delivery and wrong order

I placed an order at 15:45 for a large pizza double stacked. I was told the order will be delivered after 40 mins. I waited until it was 17:45 to ask where my order was. The lady I spoke to was Rose, when I called the second time I requested to talk to her. She said she will call the delivery guy and ask why he hasn't delivered. Rose called me after 5mins, telling me that the delivery guy had an accident so my order had to be redone. The delivery guy finally came at 18:30 pm . The order was wrong. The worst pay of it when I checked the slip, my oder was only entered into the system at 17:50, which means it was only entered after my second phone call. I'm really disappointed for such bad service. I had visitors at my house. I am so embarrassed. I then called the manager and he offered that he will make me the right order and only charge me 50%. For me that is ridiculous cause the rule says if the pizza is cold you don't pay for it. My order is as good as being cold. Never has I experienced such bad service. My visitors had to leave without eating. Such an embarrassing moment.