Anon,
I can understand your frustration and you have every right to feel annoyed! It is likely that all this behaviour is just because it's the start of term, there away from home for the first time and they are just wanting to 'live it up' a little. Most probably after a week or two they will be tired of getting drunk and will settle back to the fact that they are there to study (assuming that your housemate is also a student).
I would try not to react angrily when they are there, as it may encourage them to knock on your door more or to be more of a nuisance, so though it's irritating it might be an idea to put some music on and to try and drown out the noise or to get some earplugs. I know it's tough but try not to let it wind you up!
Of course you need to be able to sleep and to feel comfortable in your own space. So you could try and speak to your housemate again, at a good time. Try not to use attacking language ('You..... You......You....' or 'Your friends.....' and 'your friends....'), but make it clear how you feel, e.g. 'I feel hurt because I feel my wishes are not being respected. I feel upset because this is my accommodation too' If your housemate still refuses to listen, then you might need to make it clear that you are going to raise it with the landlord if it continues.
All the best,
Oluwatosin – 3rd year student – University of Huddersfield