I need sum advice on a friend problem... Help?

Ok so, here's the situation... I have a friend tht is a girl. Known her for 3 years, I believe tht we are very close, we talk almost every day (text and Facebook) and for the last 7-8 months or so, I've been telling her tht I missed her and tht we needed to spend together now, I have gone to visit her at work a couple times, but tht dosent last no more then 10 minets at the most! Basically she keeps telling me not to worry about and that we will hang out. Every time I bring this up, she says the same dam thing, "we will we will" now remember, this has been going on for quite awhile, 8 months tops. And for tht whole 8 months, NOTHING has happened, but yet one of her cousins can come along and set up a date and bam, it's official. I don't understand. Why is she not doing anything?? She's not tht busy, she does have a part time job, no boyfriend... I don't get it... And this is a friend who refers to me as her "2nd brother". Tht right there screams "friend zone" I know. Basically, I'm just so wore out... Tired of not getting any results, so I ask you.. What should I do? Do I keep trying and hope tht eventually she'll get around to it? Or do I just give up all together... I personally feel she has no real interest, and she just says all things just to string me along... But idk. What stopping her??? What do you guys think? Input is greatly appreciated :) thanks for reading.