I used to be in a position of authority.
There are questions we couldn't answer. Not immediately. Like, WHERE'S MY PACKAGE ??? How would I know ... there were a few million pieces in the pipeline every week to my post office alone, and few of them had any kind of tracking. We could have tracked them all, but it would take a l o t l o n g e r t o p r o c e s s t h e m.
I would like to hear that more postal people sounded like they wanted to resolve these problems quickly, but we had been running about 750,000 employees, literally all over the country. Quality varies.
Like everything else, you have to help yourself, too. Make sure the item is wrapped and addressed right. If it's delayed, have the information ready to go with a complaint. The Postal Inspectors audited complaints, to find which parts of the system gave us the most trouble.
Have a little patience. It's not the internet. It's real, solid, physical items. There can be delays and mistakes, but while it's still in the system, it cycles through and will get to you. The biggest problem is at the end, if it's delivered to the wrong place. That's pretty hard for anyone in authority to answer for immediately, when you call.