Client bug or I was scammed

This happened twice, first time I played a game 1 day, and after the game it said i was at 78 LP, then when i go to play the next day I win. I earn 22, LP and it says im at 90 LP, i lost 10 LP or something weird happened and there was no other games on my match history. Today I got on my account, after a remake when it said (+0), i realized it said i was at 38 LP when it said i was at 48 after my last game yesterday. This might just be a client bug, but I dont understand why this is happening.