customer service

Yesterday at about 19H40 my girlfriend and I was at the macdonalds resturant I went to the drive thru que and was too slow so I decided to go inside the resturant, there was only one cashier heiping a que that's growing, and the same cashier is help at the back with the food, where is the staff?, I decided to leave the que and went back to the drive thru, so I have placed my order ONLY A CHEESE BURGER, I've paid for it and at the last window collected the order but all to find out it was A SMALL CHIPS, we then went inside to report the incorrect order, first of aal the staff inside didn't apologise, she just went and tell the staff in the kitchen it was a wrong order after few minutes she gave us the cheese burger and said thank you, why would one say thank you if you didn't apologise,after all net even saying we're must have a good evening or drive safe, nothing.The customer service is really poor.