🙁 I'm sorry to hear about what's been going on. Just a thought I had though, the percentiles must mean something, so even if there is an extremely difficult test, if everyone did poorly wouldn't the percentiles still be high? (regardless of the number score).
I'm not entirely sure how much schools look at percentiles which is rather unfair especially in a situation like this, but maybe you can call/e-mail some of the schools and ask them what they would think? Goodluck though! December might be pushing it a bit late, but it if you're motivated I'm sure the schools will see that determination 🙂