Getting stuck with premades not even close to your rank

My two games of leagues I get stuck with pre-mades, and of course matchmaking is not even close. Really tired of being used as filler for pre-made teams. I am never even close to rank of the pre-mades I get stuck with or have to go against. I would not care if I was put with pre-mades that were maybe silver or even high gold close to my rank, but stop putting me against plat 2's and diamond 5's constantly. Clearly when they stomp myself and my team every time I am not close to their skill level. I don't care about their specific mmr in game modes, if they are diamond they have to have some diamond skill which translates across all game modes. Fix your pre-made matchmaking to be more accurate or let us single players opt out of pre-mades. Better yet make it so us single players have a timer where after we have played with a pre-made we won't have to play with another for a certain amount of time if you click that option. For all you super defenders of your precious pre-made team that think it would be the end of the world if us single players were allowed to opt out of your perceived fun and allow us to have our own on a more level playing field. Bottom line I will be used as filler for a pre-made and not care, if the teams are actually semi-fair.