I'll start:
'I will call you back first thing tomorrow' means 'I will ignore you as long as possible'
'The file is with a colleague' means either 'I can't be arsed to get off my bottom to look for it' or 'I have no intention of answering any of your queries, get lost'
'I understand your frustration' means, 'yes, we are dragging our heels, but we really don't care cos we only work from 9-4 and its 3 now, so I am getting ready to go home'
Anyone care to add your own???