Bad Parenting

Kassidi
So I work at an indoor playground for kids, and I basically just clean up after them and I make sure they're safe and following the rules. I've been working there for a few months now and I have never experienced a child hitting a staff member until today, and I got off an hour ago and I'm still mad. This child is around 9 years old and he was messing around on the slides and I had to tell him more than 5 times to stop standing and jumping on the slides because he's hurting other children and he could seriously hurt himself. He obviously wasn't listening and then one little kid, around 3 years old, cut in front of him on the slide and the 9 year old started hitting him like beating him and so I screamed "NO!" And then he stop hitting him. Afterwards, he kept messing around on the slide so I told him that if he doesn't stop he won't be able to go on the slide anymore. Then he was like "Watch me!" And he slid down the slide and punched me three times so I found his dad and I told the parent what happened and the dad's response was "Oh well I've been watching him this whole time and I didn't see any of that happen." Then I just said "k" and walked away. The dad knew I was mad and then after, the dad asks me "Do you have children?" And I said "No, I'm not ready for kids." And he's like "well, once you have a child you'll realize that they get crazy. You just don't understand." 
1) When the fuck did I ask for your opinion?
2) Don't tell me that I don't know what I'm talking about. Your kid is an asshole because you don't punish him. 
3) What the fuck do you think my job is? I am around kids all day long. You think this is normal? 
Anyways, I just want to know anyone's opinion on this situation because I'm actually furious. I love kids and I want to work for child welfare when I'm older, but that parent is the one that pissed me off.