Terrible service from the maponya mall

I just bought a couple of meals from Mcd Maponya 11 Dec. Order 293 Where they gave me food and and actually missed out on giving me all the items I paid for. I decided to drive back to the shop to have the mistake corrected only to find the Manager who was on duty (Alex) at the time telling me It is MY FAULT that I did not check the items. Is this the new McDonald's policy to have staff giving people less item then what they paid for?? And having customers to waste their time effort and petrol to get service like that