False advertising

I went on Burger King website and they advertise on TV that you can get a king meal for only R29.90. I took a screenshot on my mobile phone and went to Burger King. Only to be told that I must pay R10.00 more for a meal. I showed them that it says King meals for under R30.00. She ( Manager) refused to give me the meal. I had to pay R39.90 for my meal.