Case 1, Medion pre-built off-the-shelf-PC:
Emailed support about why mini-CDs don't work with the CD burner. A month later (!) got a single-line reply: "Support for mini media isn't planned right now". Thanks, jerks!
Case 2, iomega external USB CD burner:
At some point few months after i got it (new!), it just didn't burn CDs anymore. Classic iomega quality. Called support, said what the problem was, got told i was likely using "incompatible CDs" and i should be using iomega ones. I answered that i'm in the middle of a 10-pack of CDs and they worked yesterday, and some CD-RWs that had worked just fine didn't anymore. Incompatible my ass. That did the trick and i could return it, but iirc i never actually got a replacement (was about 15 at the time and had other priorities 😁)
Case 3, router, forced by internet provider (1&1) before free choice of router became a thing in germany:
The router was, at some point after ~4 years of use, very wonky and kept crashing. Called 1&1 and asked for a replacement before it would die completely. Dude on the phone asked me to update firmware first (apparnently part of their protocol?). Because attempting to update the firmware on a drunk and half-dead device is a really good idea obviously!
Of course that totally bricked it, i was without internet for about 2 weeks because the delivery service also managed to misplace the parcel and i had to travel half the county to show up at their central warehouse in the middle of nowhere and make a fuss because their phone support was incompetent as fuck.
To add insult to injury only then they "found" the package in a local phone shop and directed me there (so back into my town), and upon talking to the owner he said he stopped working with them years ago (lol?!). A few heated phone calls of the dude later it turned up somewhere else and i could get back online the next day.
That one was quite an adventure and took multiple days to get sorted out. >.<
Lesson learned: Treat your customers like they need to lose some fat. Running around is good.