I work in a flea market and she is a new face there. I talked to her 2-3 times last week and the week before and today again. We seemed to be getting on a good note...(she even punched on my arm playfully while passing by when I was not noticing her) I went out to her booth and after a casual playful interaction asked her out on a coffee. She said that she had to meet a friend so she cannot. I told her it's only gonna take about 10-15 mins so she should and then she agreed and said that she wont be able to stay for more than 20 mins. After closing my booth I went to the coffee shop and after 10 mins of waiting I texted her asking her to be quick coz she has to leave too....she called me and said that she has already left and is going to see her friend. I was taken aback and felt like a fool. I had earlier told her that I will give her a call late in the evening but I guess I am not gonna do that. How should I be acting in a situation like this to come across as a confident and cool guy? Any suggestions will be highly appreciated.