I with family and friends went for dinner to this Indian restaurant. We received appetizer after 30mins (that's fine for me) and main dishes after 45mins(even that's fine for me as well). While we are about 80% of the main dish, the waiter brought two more dishes, which we have not ordered. I said - sorry they have not been ordered for this table!
Later the manager came and started insisting. I just let it go. At the end during payment time, he charged those both dishes which showed up on the bill (i repeated, i and none of my friends ordered them). I said you can charge one of them but 2nd one, i can't. Then he removed the second one from the bill, and when i received another bill (updated), i saw GRATUITY 20% being already charged in the total bill, which is around 20+$.

I asked why you are giving tips by yourself, it should be done by the customer. He replied "if there are more than 4 people in a table, we do that". I asked "where is the rule written in the US?"  he replied "our computer machine does automatically".

I simply paid and left  saying "we did not get good service and this is not the way the customers should be treated"
(it was my kid's b'day today, and we did not want any  unnecessary environment to be created there)

(there were not many cusotmers either; when reached around 730pm, there were only 5 tables being occupied and later just ours and another)

First of all I paid 14$ for the dish I or none of my group members ordered it   ===> i can consider this as assuming the waiter misunderstood us while taking order. That much of money was not too big for me either, however, I am simply upset by his behavior and that 20% tips already charged(???)

my main concern is 20% GRAUTIY fee and  that guy's behavior. 

In this situation, what would you have done... How can it be reported and where? or whether it is good to report to police? or forget this matter??