Truely infuriating service

I must say your staff at McDonald's Umhlanga on Umhlanga Rocks Drive, Durban, South Africa really need to pull up their socks, it seems that every time I am working night shift and go to get a Milkshake they suddenly don't have any, not to mention how I sat in the drive through for 30 minutes tonight and ordered a meal just to get to the pay station 30 MINUTES LATER because for some reason the window was closed, to be told there is no stock of the item I ordered...... really pathetic experience, either the staff just don't give a damn or the managers have no skill when it comes to keeping up with stock, maybe I should change my restaurant choice after having many previous sour encounters with this particular outlet