Task: Categorize the tweet's emotional tone as either 'neutral or no emotion' or identify the presence of one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: @SalterUK second pair of scales I have bought that have stopped working after battery change. Is this an issue you are aware of?  #unhappy
This tweet contains emotions: 
anger, pessimism, sadness