Restaurant Service 101: What To Do To Piss Off A Customer

Today, the family went out to celebrate Cathy's birthday. We decided to go to a Chinese restaurant and it really was the worst experience we have had since we have been in Vegas.
We went to the Asian Buffet- Little Dumplings restaurant in the 2500 block of W. Craig.
We had a coupon that stated that if you bought 2 buffets at the regular price, then a child 10 and under was free. Well since our son is 10, we thought that should be a no brainer, but no. When we got to the restaurant, their sign in the restaurant said under ten gets the discount. We argued for a bit. They argued that their signed overruled the coupon. I argued that words means things and they ought to honor their coupon. We were only arguing about a dollar or so, but it was principal of the thing.
So, I won and we got the discount. So, we got our drinks ordered and I went to the bathroom. When I got back, my daughter was soaking wet because the waiter spilled a glass of ice tea on her, accidentally, I think. The waiter never apologized.
The food was so-so and service to the table was poor at best.
When it was time for dessert, my daughter who is allergic to nuts, wanted some dessert, but the desserts were not marked. So, we asked the waiter if their were nuts in any of the desserts. Mistake!! It would have helped if the waiter understood English. It would have helped if anyone understood English. So my daughter had vanilla ice cream, which was a little disappointing.
When I was in the bathroom, one of the toilets had poop on it , there was gang graffiti in the stalls and soap was out of one of the dispensers.
So, in the end, I left a $2 tip- why I don't know.
They lost us as a future customer and I am sure we are not the only ones.