What to do when police won’t take an assault seriously?

Last night at a fair a girl that I’ve had problems with hit my leg with her stroller really hard on purpose cause my leg was out when she was walking by. When I told the police that were there what happened, they acted annoyed and like they didn’t care. After getting her statement they told me that she didn’t hit me with her stroller or at least not on purpose when she did, and that they weren’t going to arrest her or pursue charges. After arguing with them That she intentionally rammed my leg and showing them my leg that had a small red mark on it they took a picture of it, they told me the report would be sent to the state and they would let me know whether they’re going to pursue charges or not. Even when I tried telling them I had a witness they still acted like they didn’t care And tried pretty much shooing me away. I’m going to the police department Monday to make sure the report was sent in. I really want to press charges against the girl but my only witness left the fair before being able to talk to the police so it’s my word against hers. What can I do?? I also didn’t get the officers name which I should have...