Task: Identify the primary emotion conveyed in the tweet and assign it to either 'neutral or no emotion' or one or more of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best capture 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