Entitled parent

Backstory:
So I'm a 16-year-old girl who is a total nerd. I love superheroes, video games, and I'm a huge collector of comic books. I work at a comic book store (which I love by the way). This store is fairly large but in a recent expansion, they started selling toys(Which were mainly vintage collectibles).

The way people sell stuff to the store is through consignment. Consignment is when the store basically says you can keep it in the store so that way people can buy it but we split the price 50/50. The store keeps a detailed record of all the stuff they consign from people. I got a list of items from a guy who wants the products sent back to him because he's moving.

My job today was that I had a list of items highlighted that I needed to walk around the store, collect, and record that I collected it. These items are ID'd by a tag system where the price tag will have a number on it which tells you what number the consigner was randomly given.

Okay, so I had a bunch of action figures I had to find in the star wars area of the toy section. I had a bin of items that I'd put the toys with the consign number then I'd mark it off on the list. Today most of my Co-workers were working in the storage/backroom/warehouse area of the store so it was just me and another lady(We'll call her Clem (Cuz she was really into walking dead)). I put at least 15 different figures in this bin before maybe 15 different customers including a woman and a kid who is probably around 7-8 years old come through the door and most head over to the counters to ask questions about comics and etc. Once these customers come in Clem gets overwhelmed and asks if I could come and help some of the customers. I place the lid on the bin with the toys in them and write on a letter
"STORE PROPERTY- DO NOT TOUCH" In big letters.
The store policy because we have a lot of vintages and expensive items kids are not allowed in the toy or comic section without an adult. These two completely ignore that and EP goes and starts looking for Deadpool comics for EP. The store has a kid section of comics near the toys but the mom buys the comics that are rated M for her 7-8-year-old son. This kid is extremely loud, running around, screaming, dropping stuff, and knocking stuff over. Clem is dealing with some customers so I go ahead and decide to confront the mom about her kid.

Me: Yours truly, EP: Entitled Parent, EK: Entitled Kid, Clem: My Co-worker.

Me: Excuse me, ma'am. I thought I'd let you know that store policy is that children aren't allowed to be out in this section of the store without supervision. We have some vintage items that we sell through consignment and we don't want him to damage anything.

EP: It's his birthday tomorrow. I told him he could play with toys. They are toys and if they break easily then clearly you shouldn't sell them.

These items really aren't toys for reckless kids, they are actually more like collectibles with some having 100$+ prices.

I'm trying to get her to watch her child when all of a sudden I hear a loud
WIIIIISSSHHHHH
noise followed by him screaming
"HAHAHAHA I BROKE IT!!!!"*

I immediately run over to the area where I was putting figures and this kid has dumped the entire bin out of the ground. He has opened one of the figures and snapped it in half. Now Clem was helping some other customers and I'm an employee that was supposed to be looking after these items. I just stood there in disbelief as this kid kept smashing boxes together like he was a giant Darth Vader.
I stood there in disbelief for a good 2 minutes. I was terrified that they'd get pissed at me and I'd have to find another internship to finish my hours. EP didn't move an inch, she just kept looking through Deadpool comics like her child was an afterthought.  I was pretty pissed at EP and EK but eventually, Clem came around and saw it and almost had the exact look on her face like "I'm so fired..". Eventually, she told me to get the toys back in the bin because these items belonged to someone else and if EK keeps breaking them the store is responsible for damages. I go over to the kid and start putting some of the figures back in the bin before he runs over to the bin and starts yelling at me very loudly.

EP: NO!!!! THESE ARE MY TOYS!!!

Me: Do you mind if I play with them for a bit?

EP: NO!! THEY ARE MINE!!

He then tips the bin back over spilling the figures back onto the floor. I don't say anything, I flip the bin back over and start putting away the figures even quicker. He notices this and runs at me and bites my hand(Which really fucking hurt). I'm trying to get the figures put away before the kid gets me into even more trouble. I basically peel him off me after he kept kicking and punching then he soccer style flops onto the floor. He instantly starts screaming

EP: MOM!!! THE GIRL HIT ME!!!

Luckily EP either didn't hear it or didn't care because she never came over. While he was sulking on the floor I basically put all the figures in the bin and pry one from his hands.
I grab the bin and go and place it behind the counter where neither the kid or mom is allowed. The kid is basically sitting on the floor near the star wars collectibles not crying but pouting. This kid has damaged at least $150 worth of store collectibles that are consigned from a customer. EP eventually comes up to the counter and Clem starts ringing her up. Now she only had around 5 comics in her hand which adds up to about 20ish dollars however because of the damage the kid did to the items she charged the lady an extra $150 to her purchase. EP starts flipping out.

EP: ONE HUNDRED AND EIGHTY-FIVE DOLLARS?!!?

Clem: That's correct ma'am. Due to the damage caused to our items and in accordance with store policy you must pay us the amount of money due to replace those items.

EP: MY SON DIDN'T BREAK ANYTHING! IT'S HIS BIRTHDAY TOMORROW! HE SHOULD BE ABLE TO PLAY WITH WHAT HE WANTS TO PLAY! MY SON IS SO RESPONSIBLE FOR HIS AGE, YOU JUST WANT OUR MONEY!

At this point me and Clem are basically giving her the "are you fuckin' serious!?" look. I open the bin and pull out the 9 different vintage figures that he damaged and pretty much point out exactly what he did to them including the one that was snapped in half.

EP: Maybe you shouldn't sell such expensive items if you are worried about them getting damaged!

At this point me and Clem gave up.

Clem: Look ma'am you can either pay us the money you owe us or we can call the cops!

EP argued for at least another 30 minutes about how our store should hire people to watch kids so parents could shop, etc. After we kept threatening her she eventually paid for everything, grabbed her son by the wrist and left the store in a hurry. Luckily Clem and I never got in trouble for this as our manager saw this as the fault of EP, not us.