The post offices in Brooklyn and Queens are typically quite terrible and do really shitty things like mentioned in the OP all the time. My brother has terrible problems running his business out of Sunnyside because of problems caused by USPS.

There's no accountability in these post offices for how they deal with their customers.

I'm glad almost all of my Prime deliveries are via UPS or FedEx. Occasionally they go through USPS or through them via FedEx SmartPost and those are the only ones that ever have problems.

My post office in South Carolina is pretty crap too. If the carrier calls out sick, nobody delivers the mail that day. Every once in a while there will be several days of this and then my mailbox is stuffed with all the mail I should have received. Or something arrives 6 months after it was sent.