I did French GCSE and got an A* overall. My advice is to listen to recordings in your target language, like TV shows you know well (DVDs have language options, I think?), songs, or the news. It's great if you know individual vocab words, but if you can't hear those words when they're spoken in a sentence then they're useless to you. Fully immersing yourself in the language by listening and focusing on the sentence as a whole is (in my opinion) the best way to learn.
Past papers are a must. Make sure you do as many as you can before the exam.
Do you make notes while the audio is playing? My teacher always told us to write down anything we heard, but I could never focus, because I was too busy stressing about having to write stuff down while they're speaking. I'd recommend not doing that, and instead devote 100% of your attention to listening to the speaker and making links between what's being said and the question.