Pathetic customer service received from SPUR WATERCREST MALL

Had the most terrible experience at Spur Watercrest mall Ordered a chicken schnitzel and whilst eating had noticed that the mushroom sauce tasted off and sour... Told the waitress who had then informed the manager who came up to the table and explained that they use the same sauce for everyone and it's not his fault... He then said that I had eaten most of the meal and he was going to charge me for the entire meal!!! He then brings another guy who tells me the same thing and both never seemed apologetic at all! He then goes to state that he does not see the logic of me not wanting to pay for my meal... At the end of it I left hungry, yet put off from ever eating at spur again and I wasn't even apologized to People like Liam and Owen from Spur Watercrest mall should not be in the food service industry because they insult their customers instead of helping