I use Amazon all the time. I have Amazon Prime and they got one package to me 24 hours after I ordered it.
While no company is perfect, Amazon is about as close as you can get. I too have Amazon Prime. Awhile back I was promised that an order of mine would be delivered on a Tuesday. Tuesday came, and no delivery.
When I called to inquire about it, Amazon gave me an extra month of Prime free for my troubles. That's treating a customer right.