Slow sales person, incorrect order

we decided to take our little ones out for ice-cream, because of the lack of attention from the Drive thru attended where i had to literally repeat myself 8 times for her to get the order correct at the time of placing the order still lead to the being incorrect, while placing the order we were pestered by a begger in the drive through, being good citizens we decided to buy the gentleman a meal, and heres where everything gets messed up, intial order was for 6 mcflurrys in total, 5 oreo and chocolate source, and 1 strawberry, and a big mac meal, and an extra coke, we collect the order and realize that we were given just oreo mcflurrys, we sent it back stating that theres no chocolate sauce, they take it back for a few minutes, and return it to us, we ddnt check the second time around, only to gey home and discover that they did not add in the chocolate sauce and after looking at the slip for contact details we discovered that we were charged for 2 extra cokes instead of 1