Was not aware that a 15% tip had already been incl...

Was not aware that a 15% tip had already been included in our bill as the party was over 12 people.
So waitress let it slide when we added our regular 20% tip to the cost of the meal, which was $54
With our extra tip, the final cost was over $80 : 2 half salads, one half pasta dish, one bowl of soup, and a glass of wine, $82 !!!!!
If I had been the waitress I would have been kind and informed us that the tip was already included
I wonder how many others of the party got " taken " as well, very disappointed, but was warned about high prices there