Disappointed Service

I am so disappointed in the service I have received from the Samsung Appliance store in Clearwater. On Saturday, I bought and paid for the top of the range dishwasher and was told they would deliver on Sunday. Within 10 minutes of leaving the store, they phoned to say that they are unfortunately out of stock and asked if they could please deliver on Tuesday (today). At 14h30 I had still not heard anything, so I phoned and was told they would find out where my dishwasher was and get back to me. At 16h15 I phoned again, only to be told that there is no stock and they will deliver tomorrow. Two years ago, the exact same thing happened with my Samsung washing machine - after fighting, I eventually got my washing machine two weeks later. What is wrong with Samsung that they cannot follow through with their service? Why is there always an issue?