Untrained staff

Absolutely horrible service from Delmas Wimpy. I order 2 schitzels with mushroom sauce. The waiter (Mirriam) explanied to me and my co worker that the mushroom sauce costs R15 and the cheese sauce R 10. I wanted to substitute my mushroom for a cheese sauce. She said that because there is a price difference she cannot substitute it I have to pay R10 extra to substitute the sauces. When I got my food I asked her twice if my sauces is there before I leave and she said yes When I get back to my office here is no cheese sauce. So not only did I have to pay extra for a cheaper sauce but I didn't even get the cheese sauce. Call me and explain this to me. Servaas van Staden-Coetzer ***