[{'role': 'USR', 'utterance': "I haven't received my credit card bill yet."}
 {'role': 'SYS', 'utterance': 'Which credit card are you speaking of?'}
 {'role': 'USR', 'utterance': 'My Master Card.'}
 {'role': 'SYS', 'utterance': 'We sent that bill out a couple of weeks ago.'}
 {'role': 'USR', 'utterance': 'I never got it.'}
 {'role': 'SYS', 'utterance': 'Your bill was mailed already.'}
 {'role': 'USR', 'utterance': "What am I going to do since I haven't received the bill?"}]
{'role': 'SYS', 'utterance': "If you haven't gotten it yet, then you should probably take that up with your post office."}