Key shards

So after the Q&A on key shards I went out of my way to try and comply to them to increase my odds of shards. Needless to say it has been MONTHS since I have earned even three shards. I feel like there is a purchase scam where if you have purchase a key the game drops your odds entirely so you keep buying. I am always ahead of my boxes and receive plenty S- and above with wins. Having 6 boxes and no keys is starting to piss me off! is there a bug? or something I am missing? I just cant help but think im bending over for a #RIOT