Nando's: Lies about prices and doesn't listen

There has never been a time when I have ordered for collection and my order has been what I have requested. If you have the option to place an order for collection and you have a all centre dedicated to taking orders, how do you still get things wrong? Tonight I ordered two half chickens, each with a side. One was hot, the other was mild and both were to have extra basting sauce. One side was chips and the other rolls. I also ordered a starter portion of chicken livers. The order, once collected, turned out to be both mild, both had no extra sauce and cost R94 each, not R84 each as advertised on the website. When I placed the order telephonically, I made sure to ask the operator to repeat the order and to confirm that each half chicken order was R84.

Now why do I still get the wrong order? And get charged more?