Lp system

I win 5 in a row after winning a ton and getting promoted. So I win 5 in a row. So you'd think im at 100lp and in series. I had 96 lp Ok so I win again. 116lp get into promos. I lose one so I'd now be at 98lp(I usually lose 18lp a loss)(Also op.gg told me) then I won. So now i'd be at 118lp. Then I lose another promo(Shit players both games due to loses) So now I'd be at 100lp right? Math says I should be at 100lp if not higher. Now im at 82lp So riot stole 18lp from me. (Should be at 100lp) (Win again) (Should be at 120) but instead im in promos. 2 loses and I should be at 80-85lp. Now you're put at 60lp. Taking another 20lp. The lp system steals lp from you all the time. The added 22lp gained and 18lost never adds up. That is also stolen. If you're stealing 2 wins from me and I have a 60% win rate (6 wins 4 loses) Should have 40lp left over. But instead the lp system takes it from you. So even with 60% win rate you will not climb. And for more reasons. The lp system should be trashed like your mom.