What is a polite way to say no?

[determined one]

I am still on my quest to become a member of Alpha Kappa Alpha Inc. The chapter that at my school is still suspended.From what I have been told there is no hope for the fall. My problem is that their is a member of Delta Sigma Theta innn my class and she is really nice she represents her org well.She has invited me to alot of events this pass school year she has even given me her number. Informing me that there will be a line in sept/00.I have told her that I am not intrested. She doesn't even know what org I am intrested in she just knows its not her's.(I was told to be discret) How can I tell her that I am not intrested in her org. She is so nice and helpfull.There was a spring line of DSt at my school.