Help...i need this song

not sure if anyone can help i am trying to find the title of a song. I heard this on a pirate radio station called Centerforce in 1989 and never found the title out and to make matters worse the old cassette it was on has now chewed up ! i can only offer some of the lyrics as follows.

I'm not the little girl that you once knew
but now i know i don't need you

now that you used me
i won't let you use me know more

another line was "why did you leave me lonely " with the Why repeated 5 or 6 times before the mainline..tried searching the net on these words but to no avail

it was a woman singing it

not much to go on i know but maybe someone will know it

Steve