Task: Assess the emotional content of the tweet and classify it as either 'neutral or no emotion' or as one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best represent the tweeter's mental state.
Tweet: @KitchenAidUSA  I spent over $500 on your mixer, yet the dough hook chips in my dough.  I buy a new one and the same thing happens. #unhappy
This tweet contains emotions: 
anger, disgust, sadness