Task: Classify the mental state of the tweeter based on the tweet, determining if it is 'neutral or no emotion' or characterized by any of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: Even after @O2 ref the £5k fraud, they still treat me like dirt. No returned calls or apology #shocking #customerservice @mse @resolvercouk
This tweet contains emotions: 
anger, disgust, fear