The OP was told 3-5 days, they have every right to be upset if after the 5th business day they do not have their device back. If I was told 3-5 days and had to wait until the 9th to get an update, you can bet that Apple would get an earful form me. As others have stated, Apple has set a very high bar when it comes to customer service. if the phone will not turn on and there is no damage, it should have been replaced on the spot. There is nothing they can do to 'repair' the device. They will end up replacing it anyway, so why inconvenience a customer?
Taking care of them properly doesn't always prevent 'wear and tear'. But at the same time, some people don't put that much importance on electronics, no reason for warranty to be denied because someone isn't babying a product. 5 years ago, I had a 2009 MBP that had a dent on the top casing. I had a logic board problem, Apple volunteered to replace the screen with the logic board because of the dent. Not a chance in hell they would do the now. They have definitely changed.