Ranked Play suggestion

I am having a difficult time getting out of silver. I am doing everything I believe I can, warding, helping, not flaming etc..but I still lose and get demoted. I believe riot should implement a safety net in ranked play. If you are the only player to receive an S (S-/S+) than the loss should not trigger a demotion. Several times I have been demoted when I get an S+ or S- and I go 18/4 while my team is 0/20. Just plan in simple there are just bad players out there, some teams just don't mesh, while others cannot play nice with one another, and some people just cannot be carried. I understand these facts; however, why should my rank suffer when I clearly did everything right (The S indicates this) and still be punished??