You have the option to dodge the trolls... and don't take it. Ranking deserved. 100%.
Proper Climbing Technique is a critical element in learning to climb, you have no one to blame but yourself for playing in auto loss matches. Any match you lose where you don't op.gg every player on your team, where you choose not to avoid playing with a troll, where you actively decide to play with an extremely low chance for success, you deserved to lose. Dodges cost nothing. They are free except for the time you have to wait between games. Use them when you are supposed to use them.
Don't get me wrong, I'm of the opinion there should be a zero tolerance policy for trolling in a game, but Riot hasn't implemented such a policy and DID implement a dodge system so we, as players, could make the call to avoid playing in that type of situation. Choosing not to take advantage of all your options is your own mistake. Promos or not, its doesn't matter since the only thing that matters below D1 is MMR any ways.