Given a real-life anecdote of a complex ethical situation, judge whether or not a specific person is wrong here. Answer 'not answerable' if more information is required and 'answerable' if all the information is sufficient to answer who is wrong in this situation.

Long story short, went to a korean bbq in vegas. There were only like 4 other small tables (including us) and a large one. All you can eat korean bbq was $30 per person. Any leftovers will be charged. Asked for the menu after our 1st serving because she took it. Took a while to bring the menu and didn't even give it to us, just left it on the table next to us. I had to get up to go grab it. 

Ate a few different kinds of meat and finished our side dishes. Server took forever to replace our side dishes (we had to ask). Took forever to refill my drink. After our 3rd plate of meat, we ordered one last plate. Server decided to bring a WHOLE plate and immediately threw it all on the grill. I was like wtf, we can't finish this and I wasn't about to be charged for not finishing that shit so I took it to the restroom and threw most of it in the trash.

Went to pay in the front cashier. Total came up to 62.79 (two of us), payed with credit card. Service sucked for a place that wasnt even busy at all so I left a 2.21 tip to total it to 65 on the receipt. Cashier told me 'No, that tip is too little. We're not a buffet, we're a restaurant. You need to tip more." She pointed to the bottom of the receipt which had 3 gratuity tip amount from 11.00-13.00$. I looked at it and thought about it for a bit and told her "No, I bought the ALL YOU CAN EAT KOREAN BBQ for 30$ per person. I'm not gonna give a tip based on the amount of the total. I'm gonna give the tip based on the service that was given to me and the service sucked". She got mad and left angrily to seat the customers that was waiting behind us and we walked out. 

AITA for not tipping what the cashier wanted me to tip?
answerable