Oh No!! Not an angry note!!
Don't underestimate the power of an angry note. My Dad once wrote an angry note to Zenith (they make TVs among other things). His gripe was that it stopped working 4 days before the warranty expired. It had a 10 year warranty. Sure enough, they sent a new TV, since they didn't even manufacture or have parts for that ancient model that my Dad had anymore.
But why did EU fine MS? What they do is maybe unethical but it is entirely within the law.