severely unbalanced matchmaking system

I just played a game where the enemy team had 525 more LP than my team did. They also had 747 more games played. now, we did have one smurf with only 16 games played but that 1 player isnt going to make up the difference of 7 HUNDRED and forty seven games played. The enemy team has much higher rank indicating that their MMR is also higher as well, but NOBODY KNOWS because riot doesnt tell us our MMR BECAUSE they dont want us to know how broken the system actually is. the enemy team ALSO has more experienced players creating a gap of 747 games played more than our team did. I am diamond 2, I was playing support. My adc was diamond 3. We had to lane against a s5 challenger adc who was playing lucian and absolutely dumping on my adc in trades. How can this ever possibly be considered a balanced matchmaking system with ALL of this going on? in just ONE game. its actually the biggest joke and riot knows it. and proof that they know it but don't want us to figure it out lies within them not telling us what our MMR actually is. nor do they tell us how they got this "number" that is supposed to make for a balanced game. Hey Riot, how about you fix your system cuz it is DEFINATELY NOT FAIR. or at least how about you tell us what our MMR actually is. Why are you hiding it?