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: @Rocks_n_Ropes Can't believe how rude your cashier was today when I was returning an item!  Your customer service is slacking. #terrible
This tweet contains emotions: 
anger, disgust