Billy G can charge wat they want no matter what was advertised on the sign

The rates as advertised is not the rate that you pay. We had a appointment for today. It is my birthday today. Outside the restaurant is says discounted rates for rewards customers. As well as free meal for 1 person on his or her birthday. When we pay they says that rates is not valid anymore. It was advertised outside the door. The national consumer act state the price you see is the price you pay. But not according to Billy G at Goldfields Casino in Welkom. We paid the full price.