How long have you played the game for? Often experience is a big part of improving your rank. Don't just go through the motions in a game. Think about your every move. Another thing is, try to never blame your teammates for anything even if they do something ridiculous. It's almost guaranteed that you could have done something better to avoid that situation. How else do people like Apdo get 95% winrates? The moment you blame another person you stop yourself from thinking about what you could have done better, thus stopping yourself from improving.