What else should I have done in this situation?

Yesterday I saw a girl leaving a store and she was carrying a lot of stuff, so I opened the door for her, as she got out of the store she looked at me angrily and said "I don't need help from you men, I can do it on my own."
I was not sure what I did wrong here and was also not in the mood to fight so I went in the store.
Maybe she was angry about something else and lashed out, but what else could I have done in that situation?
What else should I have done in this situation?
Post Opinion