Steers with bad service of short yet fully paid order

I placed an oder around 6pm at steers engen hatfield, driver came to deliver only to find there was 1 burger short, we called him back he said he is going back to the shop he just delivers, he was rude and hanged up on us. Called the steers line it kept saying they have high call volumes till airtime got finished. I sent them email not one is coming back by that time full amount of R350 is paid to get a short order.