If she was actively working with you to resolve it, then you could excuse the time it was taking, but considering that she seems to be dodging you, I would leave the negative feedback, even if you do get a refund because it was still a poor transaction etc. I don't know if that would harm your chances of getting a refund though, you might have to look into that further. The only issue is that they can reply to neg feedback and it's usually not nice when they do.

ETA - another thought, usually when I am not 100% happy I leave neutral fb, that way I can still voice my issues even if things were resolved eventually etc.