Exxon review: manager

Every time I walk into this particular gas station, the manager I believe and she is a black woman, when she is there working cash register I greet her in the upmost respectful manner no matter what mood I'm in. I'm a black woman also, she never greets her black customers or smiles and that is very unprofessional behavior. She will greet the Caucasian individuals and I feel she is being very bias no particular reason at all. Maybe she has personal issues but it should not be brought to work. I would like something to be done about it. That's money being lost because of her attitude and I love shopping at Mobil gas stations. I don't want to cause a scene on the premises or anything.