BAD ATTITUDE AND LACK OF SERVICE

I want to McDonald's Sunward park in Boksburg to buy my children food(Kiddies Meal) via drive through and we've waited in the que for about 30mins - an hour, I gout the meals but when I got home only find out that one of the bags had no fries in it then I went back to report for them but the attitude that I got back from the sales people was repulsive..... So disregarding and disrespectful. First of all how do you attend to your customers while there is food in your and chewing no apologizes from the person non what so ever and this not the first time.