Dear Akin B,
First and foremost, how dare you ask a girl for her pin? What is she's using it to hold her skirt together?
You see, asking her for it signified to her that you had seen where her dress was torn and you didn't have the decency not to draw attention to it. Amateur.
Secondly, something tells me that if you did not ask for her pin first (and God only knows what you intended to do with it) she would have told you it is rude to ask her a girl for her number.
Her friend was right; you fucked up, but not by asking for her pin. I think you could have asked her for her number, her pin, her weave, her toilet roll or anything and she would have given it/them to you if only you had asked in Auto Lounge or somewhere like that. You see, places like that just have a quality that makes people want to give people things - unlike suya spots, popular or not.
I have answered your question; now go and be unprofessional no more.