Lost LP for a game that I actually won

Hey riot.

I know there is no way to get my LP back, but please you have to fix this. I won a game as thresh in ranked, went 3/2/17. When the game was over, in the post game screen, I got a D- and it said (Victory -17 LP) Indeed, I checked my ranked lp and I did lose 17 LPs, and I won that game! In my match history, It says that I won still, but my LP is gone! It was really a tilter, and I wish that kind of thing to no one, so please ffix it