Promos need to go

In the past 2 days I have been in my promos twice. Each time I have ended up on teams that has been how we say rough. Last game of one we did fine until three of them decided to go to baron and all die FROM BARON. The opposing team proceeds to go down lane and win. I of course, under the current system, am punished and loose LP because that was my last promo game. I do not understand how I can do well in my promo games but my team be horrendous and I be kept in my current rank. It just makes no sense to even have promos. Wouldn't the fact i have won X many games to get to the promos be proof I should be above the rank I am currently in? I am not pretending I am amazing at this game or without error.