Bad service at McDonald’s

What a bad and humiliating service I received at McDonald’s at R55 in Monavoni. I installed the app because my friend told about the great specials they give on the app. After installing it said I have a freebies burger. I redeemed and was talking to the cashier on the line. She was so *********** and said she cannot hear me I should come to the window and there was a queue and by the time I got to her the time to redeem was over and she said there is nothing she can do. She was so arrogant, I kept requesting for the manager and she kept saying there is nothing she can do. I then raised my voice requesting for the manager and she went to call the shift supervisor (Angel) who was not helpful at all. Both of them have no customer service. I wanted to buy something else but the service I received just made me drive through. This is unlike the MacD service we know!