Poor Service at Kauai

Bought a Steak & Avo Quasadilla and a Large Gem smoothie . On the board the Steak and Avonwas price at 97 and Gem at 61 , but to my surprise I was told the system went offline and I was charged R219 for a meal which was suppose to cost me R158.00 . I wasnt given a receipt so I asked "Are the prices on the board what you are charging ?" Thus when I was told , I will give you change . Something is not right there