Just remember that all airlines will reject your first claim in the hope that, as a large majority do, go away. You have to press on. It's true that those of us with inside information can have an advantage. I had that experience when Eurowings cancelled a flight on me several years ago. They pretended that the aircraft had gone tech (at its base - our dep point) for unforeseen reasons just before departure. I proved to them that it had gone tech 6 hours prior to our ETD and that they had had plenty of time to come up with an alternative arrangement. They coughed up without further argument.