Rogue cashier and poor service

Went to SImply asia on Monday the 8th August at the glen branch and boy was that a mistake... I waited 10 minutes for someon eto come help me at teh counter. when a lady did arrive, she took my order and punched it on teh system. She then charged me R300.00 odd fo rthe order and did not give me a slip. Sh esaid that i can go and sit in teh food court and wait for my order.. I insisted on a slip as this is what i do wherever I go, having being fleeced of money before. She then printed my slip and lo and behold the order was R258 odd. I asked her as to why this was so and she said something feeble like oh im sorry, i did not charge you for the corn cakes.. interesting as she knew what the corn cales cost to give me th initial price of R300 odd. Strange . Dear franchisee you are being ****** at your store!!!. I then asked her about the waiting time and was told that it will be around 10 to 15 minutes. This was at 18.16. we received our order at 18:55..... almost 50 minutes later and there were only 1 other customer at the store... Pathetic service