Price increases with no notice

Going for my usual breakfast at McDonalds in Brentwood Park, Benoni, the prices stated were not what was charged. "Prices have gone up," I was told. That's *******. There was no sign to say so. They cannot show a pricing structure with pictures of the various foods, and then at the pay window ask for another 20%! I drove off. They will NEVER see me again. Not ever.