Maybe what you experiencing is a first dose of what most of the world is like most of the time. There is no law that says you must be pleasant to people. While it is better all round if people are, the plain fact is that there are many who aren't and indeed there are plenty of people who enjoy being foul, either openly or secretively.
At least you have been able to ascertain these people are foul, which may mean they are open about it.. The really nasty ones pretend to be your friend, to be vulnerable and need your help, to be one of the gang etc but are back-stabbing as many as possible along the way.
There are massive drop-out rates in most universities, so many of these people may simply not come back next year.
You must ask yourself this: did you go there to be best mates with these people, or did you go there to get a qualification? If you want the degree, you smply shut yourself off from the rest. Speak if spoken to but don't seek their company or approval. Find a group of friends and associates that you like.
If you don't want the degree, leave, change course, change university or do something else.