Maybe it's something to do with the both of you
I can count on one hand the amount of times a Prime shipment hasn't come when it was promised. And I usually just use the 2 day Prime because it's free with having Prime, I rarely NEED anything that quickly. And the couple of times I have had an issue, Amazon took care of it right away and overnighted me a replacement at no cost. And when the original item came, once they just told me to keep it and the other time they sent me a label to put on the box to return it. They even scheduled the p;ick-up so I didn't have to take it to the Post Office.