Hit and run... minor damages?

i was parked and some suv backed up and hit my toyota. craked my bumper. i turned on my car and horned he drove and did not stop i backed up and followed the person horning and high beaming the car. it does not stop .. i followed it and got the license plate number and it kept going into some alley way so i stopped headed back and went to the police station. they said they couldnt find a math on the license plate number that i provided. and they werent goin to spend all night looking for it. so what can i do bout it? nothing? i dont want to go to my insurance what if it goes up?