Hextech Crafting is bs

So I got keys and chests but the last month was total bs.I got S-,S,S+ even Bs and As and still nothing.My friends, who play with me all the time get fragments even tho their score is much worse than mine?Why?I got 2 1850 RP skins frags in my inventory?Is it because of that? Even so, why doesn't it give me anything to make the essence for those skins.