Task: Determine the dominant emotion in the tweet and classify it as either 'neutral or no emotion' or one of the eleven provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: Incredibly shocked and disappointed with @united customer service. Really making me rethink flying with them in the future. #unhappy
This tweet contains emotions: 
anger, disgust, pessimism, sadness