Task: Analyze the tweet's emotional connotations 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 best portray the tweeter's mental state.
Tweet: I got a NO RESPONSE again from an #irate customer of #amazon 😞😞\nwhy can't they understand that it's not always amazon fault..\n#carrierfault
This tweet contains emotions: 
anger, disgust, pessimism, sadness