Always go to where you're constantly treated well. Screw new places.
Yup. A life lesson. Sometimes, with some things, a survival lesson.
Of course, with shippers, it's largely just an inconvenience. The more I contend with the USPS hacks that often get hired at that organization, the more I realize the definition of "customer service" pre-dated the lives of all the critters there. And most don't seem to have studied the history or utility of it.
Sign of the times, in a "disposable" society.
Nicely, that old "Invisible Hand" plays a solid part. Generally there are others who do get it, and who behave accordingly. As you say: discard the ones who don't, and stick with those who do.
One thing I miss, from a year in Taiwan years ago: that great little restaurant a few blocks up the road, tucked behind on a puny little side street. Dang, but did they make great stuff, mostly family recipes, and they valued their neighborhood residents like they were extended family.
What a place. Have long wished that every business operated in such a way, whatever their niche product/service. Everyone could learn a thing or two from that little family and their operation. Top-notch food, exceptional service, highly-valued customer base ... and never failing on any of these. They "got" it. In every way.
I've used them as an occasional anecdotal story, when I've been particularly rubbed wrong by a failing in customer service. Comes down to focus, attention to detail, respect for the task they're performing, immense respect for the customer, with an eye toward what can occur when failing on those things. Doesn't take much, but "business" isn't for everyone.