Is your placement a compulsory part of your degree? If so, I would guess that it's not as simple as just quitting.
If you are this upset about it, then definitely contact your uni ASAP- but I wouldn't quit until you have an ok from them.
FWIW, a lot of people don't go to work to make friends, so I wouldn't assume their lack of openness is anything personal. If it'll look good on your CV, can you just try to go in and be professional and not worry too much about how others are treating you unless they're being openly rude?