Shamed for Ice cream

McDonald's at Sky City has managed to work on my nerves. I ordered the burger meal that came with fries, nuggets, dip, drink and cone ice cream for R79.90. The employee who bought my food said i could keep the slip and fetch my ice cream later as i was still eating the burger. When i went back later to get my ice cream, the manager attended to me and told me i can't get any ice cream because its not the slip. He even laughed at me and even suggested that I was making it up. We went back to the screen with the menu and showed him what i ordered. He still insisted that its not showing on the slip. Who's fault is that??? Ermist or whatever he's name is, embarrassed and ridiculed me in front of other customers for a R10 cone ice cream! I'm enraged and utterly disappointed in the customer service I recieved here today. Officially wrote off McDonald's Sky City!