Hextech chests rigged?

You have to wait 6 days for a chest and then a s grade or a really really good game to get a chest on a champ in a season, with the key frags dropping like once in a blue moon and when you get a chest and 3 key frags, you are all excited to open it for an awesome skin/ atleast a skin or to some extent an unowned champion! But nope.... Riot has its own game to play ! You try so hard to collect the chests and all you get is an owned champion again and again ! Have unlocked like 4-5 chests like past 2 months probably and all i got was champions which I already have ! Typical riot.. smh [zombie-brand-clap] GGWP...