Learn English – A single word for someone who is not pleased no matter how hard you try

pejorative-languagesingle-word-requests

I'm looking for a word that means

someone (especially a boss) who is not pleased (with your work, attitude etc.) no matter how hard you try.

Best Answer

Dear boss,

You are the most implacable boss I have ever worked with. You are pitiless and immovable no matter how hard I try.

For these reasons, I'm out.

Yours sincerely...