Task: Evaluate the tweet for emotional cues and classify it as either 'neutral or no emotion' or as one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that indicate the tweeter's state of mind.
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