On a commercial prime account, I frequently find items that are listed as next day delivery only to get them in my cart, go through the checkout process and on the final page find that shipping will actually be 7 business days.
Every time it comes up, I am now attempting to get our company to close its Amazon account. It's not convenient or useful if I have to spend an hour navigating through constant lies in order to find the 1 product that actually ships when it says it will. I can go to a department store or office supply store and buy the things for the same cost in less time.
The problem is, the local stores don't have net 30 terms and we don't have corporate / business accounts with them, and it would be a huge hassle to add them.
I am guessing that since it is such a hassle to go back to the cart, pull the item with the false shipping dates, and then find another similar item with good shipping dates, add to cart, go through checkout, find out that shipping is actually 4+ days, rinse and repeat until you either get lucky or give up, they're probably not going to fix it because it makes them more money to keep you frustrated.