That should not have happened.
My first thought was that you were so low on all three chapters' bid lists that they all matched to quota without getting to your name. But you said your floormate got a call asking if she'd accept a bid to one of the three sororities you preffed - and chapters can only extend snap bids if they haven't met quota.
I'm sorry you were put in the position of showing up at bid day, certain you were getting a bid (because you hadn't been called), and then there was no bid for you. How awful.
I hope the Department of Greek Life can sort out what happened.