The problem is we only hear one side.
Not that you’re wrong, mind you.
I have watched this for a long time.
Folks who will claim something is defective without proving they purchased it, just wanting a new one.
Different story, but hang on.
There are portions of warranties that exclude customer-inflicted damage.
There is also recently one manufacturer who states if you change something (like, oh, to make it actually function), your warranty is DOA.
Let’s say you backed over it with your automobile.
Or, you mixed up your own thick, black, mushroom-cloud smoke fluid and burned the top of the loco off.
Or, you’re running an arc-welder for a track supply, and derail, taking out all the internal wiring (happens more often than you think).
No warranty.
Then, you have the moro…ooops…service folks who make it up “on the fly”, so to speak.
“Oh, you hauled how many cars? Anything more than 4 cars voids your warranty!”
Not knowing what the unit is, who made it, what the issue is (what broke) and why they did not honor the warranty makes it hard to second guess.
Personally, unless they have the parts I need, I can say I have never sent a loco back for warranty service in 55 years.
If they don’t have the parts, I find another source or make them.
Or, pitch the unit and try another brand.