Greek Girl,
Try to see if there are any teachers at your old high school or counselors who were greek. If not, ask if they have friends who were. Check with ladies from church or other organizations that you or your parents belong to. You get the idea, right? If a rec is that important at your school (and I know at some it is really important), then do your best to track it down. This type of networking skill will actually come in handy after you graduate, so you are getting some good experience here!
You need to know that a rec (1) does not guarantee you a bid and (2) is not an absolute essential in order to get a bid. In the end, the chapter members as well as potential new members engage in a "mutual selection" process. And, having worked behind the scenes with recruitment for MANY years, I can tell you, it is just that.
I truly wish you the best of luck! Please let us know how it works out for you!