False information and advertising

So I made a booking on 14 June 2025. I enquired about their specials which was the 20 prawns for R179 and the quarter chicken and 4 prawns for R119. The gentleman who made my booking said the specials were still on. So I confirmed my booking. When we arrived on 15 June 2025 and started to order we were told that there were no prawns anymore and those specials were now not available. However we could order from the main menu 10 prawns. One fails to understand this. In any case their service is below average.