Ugly Melanie (2008)

Melanie is too nice. Her mother, her boss, her girlfriends, her neighbour and even her neighbour's dog know this - and take advantage. One day, after a final humiliation, Melanie decides to change. From now on she intends to take revenge on all those who have made her life a misery; except that nastiness can't be learned in two days, especially when you've been a nice...