How to get your bff back?

Ok so today april 5 2010 went to the mall and hung with my ex bestfriend. Well she was in my car and wanted to go to a store and I wanted to run to my ex (who is also my friend) to get his wallet. Well she got all mad and was like drop me off at the store than. She has a baby and left him in the car and started walking inside so I drove off. Well she claims she chased the car big lie and so she is so mad at me. I allready said I was sorry but its my car I have the right to go where I want. Plus she always wants to drive and she dont have her liscense uses my money im always paying for gas money and always buying her food. My ex even is always buying her food. SO sud I walk away or try to work things out I do love her like a sis.