Disgusting customer service

I went to buy material for carport & paid for delivery as well. Before paying i asked the shop assistance there "Milo" if they will be able to deliver before 12h00 & he said "Oh yes, transport will be there infact before you" I told him to be serious because I need to assure my workers so that they may wait... 11h00 Milo calls me saying they'll only deliver short stock because they just realized that they don't have stock on other item... I told him is okay because at least the most important item was there. He said transport is on the way to my house... To my surprise from 11h00 to 14h30 they were nowhere... I called the company back they were very rude saying that I am not that important from other customers & they hang off the phone. I called again this time telling them to keep their goods & refund me because Im not going to allow anyone to treat me like *******. They refused & ssid they will try to deliver even though they are already closed.. I have never ever been treated like this & I feel so sick deep in my stomach when I think of this experience...