You did the right thing. $6.00 is $6.00 and even it if was $2.00. How many other customers have had this happened to them and he got away with it? Maybe the fellow is math challenged and the owner needs to spend more time training him. Yes, it is great to support the lqs but business is business. Even the chain stores, I have gone a round or two with couple Joann's stores and also Kentucky Fried Chicken and McDonald's. I expected to be treated fairly and in a professional manner after all I am spending hard earn dollars at those places of business. Don't let anyone take advantage of you even if it was an oversight or lack of training. Just think of it as helping them improve their job skills.