Got a BIG LAG PROBLEM(me and my entire team, actually the entire game)

I got a bug, just now happened on my last play...i was ready to qualify for gold 3(it was my promo) and since the start of the game we all had massive 2s lag...we could not play nothing and the enemy won, in this case i lost my promo wich is not nice because it happened because of you riot...I EXPECT A ROLLBACK BEFORE THAT LAG HAPPENED...no printscreen will help because you can't see nothing but if u tell me how can i upload a replay of the game maybe you will get it.again i find it very unpleasant to get kicked out of promo because of this and i expect a solution + something to compensate our loss.thank you very much, i just hope that it won't be a next time