Why is it standard practice for AT&T to lie about the shipment of online/phone orders?

It has become clear from my interaction with countless customer service agents in the past week as well as by reading these forums and other customer experiences, that AT&T has made it a policy to lie to customers about shipping out/over-nighting their orders. 

An order place online or by phone, will appear as "In Progress" on the website and will stay that way, even though the agent will reassure you that they made sure to speed up the order and it will arrive there the next day.

I added another line to my account. The shipment of the phone itself was delayed by only 2 days from the time the agent promised me, but we at least received it.  However, the SIM card that was sent with it would not activate - we tried activating both online and by phone.  When it failed to activate by phone, the agent assured me she would make sure we have a working SIM card the next day. She asked me if we would prefer to have it mailed or to go to the store. I asked when we would receive it by mail and she said she can have it shipped overnight so we would have it the next day and would also call us back the next day to make sure everything is working. I said since it would only take one day, we might as well get it by mail and save a trip to the store. 

Sure enough the order does not ship and she does not call us back.  Calling back or using the chat feature has led to the same thing - they say they are sorry it has not shipped out and assure me that they will make sure it is there the next day, covering the cost of overnight shipping. It has been 6 days of this now.  I would have happily gone to the store if upfront I was told that a shipping time can not be guaranteed, that it might take a while, so I might as well go to a store if I want the SIM card faster. But no - I was lied to repeatedly and told that they are certain it will be taken care of.

Finally one manager told me that they can not make guarantees about shipping and do not know why I was told that - after speaking to about 7-8 different reps.  The order is still "In Progress".

Going through these forums, it seems like this is standard practice and not an exception that happened to me. 

Why does AT&T think this is a way to run a business? Do you really think that customers will not leave after being repeatedly lied to? It is one thing to make a mistake, but another to have a policy of deliberate lying. 

You need to stop this practice, change the system that your agents use that tells them to lie, and crack down on lying.