So I was in the mall today with one of my friends looking around and I stopped by this one shop to look at some jackets and I noticed this cute girl working there. She said "How are you doing today?" as I walked in and I said I'm doing good and my friend tried to help me out and strike up a conversation with her and I got her name and I told her I was looking for a jacket for winter time and she helped me pick one out and we talked and as I was buying the jacket I asked her "Maybe we can go out sometime?" (because I wasn't sure of the next time I'd see her) and she shrugged and said "I have a guy....but maybe someday" so I said ok and shook her hand and said it was nice meeting her and I continued on. Im starting to get frustrated because it seems like whenever I ask a girl out they never want to for one reason or another, Im just trying to figure out what I am doing wrong.
Any suggestions?