HELP!! How do I deal with a girl playing hard to get?

Im 21. I met a girl a month ago. We've been on four dates and have hung out a few times. When we're together everything is great and she has a great time but she plays hard to get so bad when were not together and Im so confused. We'll have a great night and she'll tell me to call her tomorrow then she won't answer and she won't answer texts sometimes. Ive wanted to kiss her for so long but I just can't figure out if it will scare her off. She seems to like me so much when we're together but then she plays hard to get. She has accepted every date and hang out invitation and alwasy says we should hang out again. I'll talk to her on the phone and ill say ';I'll call u tomorrow'; and she will say ';ok, tty tomorrow'; and then not answer and return it two days later. I also overheard her telling her roommate that she should be getting chased not chasing someone else. Its really annoying me. What should I do? HELP!! How do I deal with a girl playing hard to get?
THis is what you've gotta do, in theory. ';I like you';