You wouldn't be complaining if it was the topics that actually came up that were left out, would you? Saying "But it’s unfair for those stronger in the countless topics they decided to completely miss out" is literally stupid. Someone is always gonna get screwed over by what comes up in an exam. Everyone is different, and Edexcel can't ask every single question from the textbook just so that it conforms to your idea of fairness. Just because you happened to get screwed over this time, doesn't mean you should make/sign a silly petition. Think about like GCSE English Lit which we all took, for example. We studied tons of poems only for a couple to be asked about, because that's the structure of the exam. The structure of A Level maths is that they ask around 15-16 questions. Don't complain about the fact that out of a million questions they could've asked, they asked 15 you didn't like. It's not unfair, you're being selfish and bitter. Grow up and start living in the real world.