This reminds me a lot of my experience with Halls when I was first at University. I was totally isolated, and eventually managed to get transferred to a smaller Hall.
Things were even worse that time around, as halfway through the year people had already established their cliques. When not studying they preferred to stick with people they had already established friendships with.
The only people who would pay me attention were, as with the OP's experiences, born-again Christians. They kept having the gall to tell me that everyone who doesn't accept Christ will spend an eternity in Hell. I had an atheist friend who recently died in a car accident, and they even told me he was in Hell forever.
Evangelical Christians can seriously stay out of my life. They were total hypocrites too. One of them preached to me how premarital sex was a sin, and how I need to "overcome my prejudice" that Christians are hypocritical. The same night he was having sex with his girlfriend (I was still a virgin at the time and was absolutely appalled by his hypocrisy), and the next day I saw him bragging to his mates about how he can "satisfy his girl", immediately before he approached me and asked if I was ready to accept Jesus yet!
And recently I got complete idiots on TSR telling me I am "big headed" for not wanting to be friends with such people (after having had such experiences), and that I am "big headed" for considering my friendship to be a privilege (after experiencing being taken for granted and taken advantage of by various "friends"). Erm no, that is just utterly disrespectful.
And there are still students at University who treat people who haven't had as much success as them at making friends (and girlfriends) with scorn and disdain, and consider them "losers" and an apt subject for ridicule and gossip. I hate those types with a passion. And people have the gall to defend them by saying they "don't know what it's like" so you can't blame them for putting down others as "losers".
P.S. I had to drop out of my course at the time (I was a First grade student) due to suicidal depression largely due to the social isolation and experience with bigots.
Of the few people I was in contact with from my course after that, one guy I originally got on quite well with ended up ranting to me about morality and politics over MSN (he said anyone who doesn't vote Labour or further left is worthless scum), before coming on to me in a gay way (he expressed a desire to fist my anus), before he blocked my MSN.
(Note he was the one who blocked, the gay thing would not have been a big issue for myself, if he hasn't pretty much decided to block me after doing it anyway.)
I am no longer in contact with anyone from my original degree course.