GET OUT NOW
I agree with what everyone else has said so far... It sounds like this organization is just asking for a hazing-related accident. If this is how they start out with their pledges, it will probably only get worse as you get further along in your pledgeship. I personally wouldn't want to stick around to find out.
Your pledge chair was able to prevent the other girls from trying to make you drink last time -- but she may not always be around to protect you.
And why should you need protection from girls you want to call your sisters???
Please believe me when I say that not all sororities are like the one you've described. I think you'll be better off joining an organization that values you instead of humiliates you, and leads by example, not by bullying.
Good luck and please keep us updated.
