Ordering

I recently ordered the galaxy smart watch. The order process went great, however the processing of the order itself is proving to be ignorant. I got the order confirmation which still says in progress. If I call the number for the order status however it says that my order is complete. So, I called customer service to try to find out the actual details on my order. I am told that it is scheduled to ship that day 1/27/2020 and that it should arrive no later than Wednesday 1/29/2020. The very next day I get an email telling me that my order details have changed. That the product is scheduled for delivery on 2/22/2020. It is now on back order. I call customer service again which case they could not help me in any way and I get hung up on ( not being rude in any way) I call a third time and am offered a $50 dollar credit for all of the inconvenience. I then ask if I can speak with a supervisor which case I do. He tells me that there is nothing they can do about my order and that they cannot contact retail stores to try to speed up the process. I will just have to wait for the back order. He asks if he can do anything else to help. I mention the $50 dollar credit in which I was offered and am told that they cannot do such a thing. My questions are. Why are we able to order things that ATT obviously has zero stock of instead of there being an out of stock label on the products? And; Why do the customer service reps give basically promises that they don't have the power to actually for-fill? I.E. telling me my order would be here by wednesday and telling me that I would get a $50 credit.