How does the ranking system work

Best advice I can give is to get a team of 6 players who you can communicate with, this often helps to ensure wins so you don't get in these situations. The overwatch ranking system is messed up.

According to the game player who scores more than who scores ranked in front of

You're shit at the game. Thats as simple as it is.

You may have gold elims, but that doesnt matter, you couldve been playing as an elim collecter like Genji, 76, Winston ect.

Kills dont win games, communication, raw skill, accuracy, game sense and wombo combos win games. So practice on this simple things (ie ult wasting/saving, accuracy, teamwork)

For the games matter a lot win/loses, if you are lucky in the firsts 10 matches you are not going to find trolls