Do i have the right to be upset with a friend who keeps cancelling plans at the last minute? ?

Well, that is sorta messed up!! Especially if she's known you foor that long. And if she's keep making up lame excuses like that, it's even worse! Try talking to her.. Ask her, are yiou mad at me? are you getting sick of me? That may make friends made sometimes, but sometimes, things have to get worse to get better. So I'd give it a shot. Becuse honestly, if she gets mad at you for asking that, and she is keep canceling on you last minute with lame excuses, then it's defnately not even worth trying and being friends with her. Because trust me... I loose more then one friend like every year because I guess drama is in everyone.. So good luck!!