friend rejected me twice - what to do?

my online friend whom I've known for 4 years now and whom I've chatted to much in the last few months has rejected to meet me in person, when I travel to her city next week.

I asked twice: once a few weeks back, and today I asked again if she would like to see me (maybe she reconsidered). Answer was a definite no.

Now I wonder how I should continue? On the one hand I cherish her for the help she has given me in studying her language. On the other hand, I'm mad because this doesn't make sense (1. She sends photos of herself to me often, 2. I asked to meet as friends, not necessarily lovers, 3. Why wouldn't she want to meet me when so many others have and with whom I had so little contact).

I feel very sad and don't know what I should do with this "friend" now. I'd like to make her feel sorry for this, but then again, I wish her the best.

And what's more, now I need to find a way to enjoy my holiday and stop thinking of her.

Long live those who believe and chase friendship/love.