You might want to try making a full report on the Polish Technical Support forum and ask them to pass it on to whoever looks after these things.
We had a language problem on the description of the Patch Notes for 2.7.1 on the French Battle.Net app… it never got corrected despite making a bug report on the Desktop App forum, complete with a screenshot. We finally had to report it to the French language Technical Support forum to get one of the Blizzard Customer Service people to take charge of it and fix it. Still took a few weeks to get it fixed…
Yes, I’m not surprised… that’s usually the answer that I / we also give.
This case might be different… since it has already been reported over a month ago and hasn’t been fixed.
If the CS folks on the Polish forums don’t want to handle it, then… so be it. Obviously, they cannot fix the error… that’s not their job. But they might be able to elevate the issue so that someone in localization can look at it and ask the developers to fix it. The CS might say that the error will fix itself when the season ends.
I guess what I am saying is… call it a “translation error” not a bug. When you call it a bug… you get the “report it in the Bug Report forum”. That’s the way CS are trained. If you call it a translation error, and point out that the blog has the correct text (ie, it’s only the text in the game that is incorrect)… you might just be able to convince them that this is something that they can get involved in. Ask for their help in solving this issue… because it is confusing now when the text says one thing but the game does something else.