I have had an annoying bug with the app "Numbers" since its inception. The problem was that since I use Swedish locale and we use commas to separate decimal numbers instead of period, which is causing confusion when reading csv files (which uses comma as a separator). Numbers could just not make sense of regular csv files, since it expected Swedish locale (comma as decimal), which isn't particularly common in CSV-files (the creator usually don't know where or who will read the file). On April 4 2016 I finally did something unexpected, and you won't believe what happened next! =)
I actually sent in a simple bug report to Apple's bug tracker "Radar", and they fixed the issue. All other bugs I have sent to Apple seems to have been auto-filed in the black hole of "works as intended", "duplicate" or simply not getting a reply at all. I had almost given up, and thought nothing would happen to this old problem - since it was so old, it couldn't have much of a chance to get fixed right? But no, filing bugs actually matters. It went fast too, in just a few weeks there was a new version of Numbers with the fix in it.
The thing is that Apple forums was filled with questions about this issue, and since we are dealing with locale (such problems are hard to find and debug), the US-sentric corporation could never realize that there was a problem in the first place. They would have to have machines running every test of every app on every locale and language - which shouldn't interfere with the normal procedures anyway (as usual with tests: you can usually only test for things you know will work - but more on that in another post). They simply needed my help, and they got it. Everyone else just kept complaining on forums - and as I said, this problem has been around since day one, so there has been a substantial complaint build up.
A side-note about duplicate radars: You are not allowed to know if someone else already filed the same bug before - since you can't search for known bugs. You need to do the work first, and then Apple can just throw it away - your time is free to them, since it has no cost it does not matter. Allowing searching on the other hand would be terrible PR for apple. The solution to this problem is called open radar, which makes radars searchable - but only if you double post your radars there as well.
I guess the lesson here is: keep complaining about stuff that is wrong, but also notify your developer about what is going on - no matter how big or small they are, they need to know about a problem in order to fix it.