I completely forgot about my experience 2 years ago and went back to eat again...
This time, they didn't list the auto-grat in bill. Instead, they just added to the credit card bill after wards!!
My bill was $26.04, I put $28.00 in total, my statement says $30.04. They didn't like what I wrote for tip, so they gave themselves a little more. I left little for a reason. They didn't do anything to serve us! All they did was took the order, brought the food (not even at the same time. 3 meals came in 3 different times.) And the bill. No refill, no checking on how we're doing, or how the food tasted, or need anything else!
Keep your receipt and check your account to make sure they don't add more amount than you wrote in.
I'm not concerned about $2 they added more, it's the principle of the fact that they did it. Very bad way to do business. A scam.