Pie in the sky = something that you hope will happen but which unlikely to happen.
E.g. His plan to travel around the world is just pie in the sky. Your plan to finish all the work within a week is just pie in the sky.
Disgruntled (adj) unhappy, annoyed or disappointed about something.
E.g. He is disgruntled with his boss. The disgruntled employee was blamed for causing the company loss. I am disgruntled with him because he is not reasonable at all.