She's probably pissed because you didn't make time for her and kept her waiting until it was too late.
Why don't you ask her out on a proper bloody date if your so interested in getting her back? If she says no then stop all contact with her, if she says yes then have an honest talk about reconciling over a nice meal or a calm and serene walk in the park even instead of playing booty-call-hookup-late-night-I'll-see-you-when-I-see-you-if-I-see-you type ways to reconnect?
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion