Tell me why LoL rank system is Bull****ing me

Tell me why that when I hit to 0 points and loss 1 game and made me demoted for 1 game. I know that if you like do bad like dying 0/10 will demote u from 1 game. Yeah understandable, but why the system is demoting me to silver 3 to silver 4. Why? I got promoted and didn't loose at the 0 point. I got promoted and moved up to 60 points and when I lost 60 points to 0 I loss one and then I got demoted. Like WTH man. I don't get a chance or what why am I getting this. I lost my game by playing Jayce 5/5/1 and got demoted why? I lost that game due to an AFKer, and I lost and got demoted this is preposterous and ridiculous. They need to change this back to the 2 chance before getting demoted. This happened to me already 3 time and this is Frustrating me. Someone tell me why this rank system is not giving people chances before demote.[zombie-brand-clap] [zombie-brand-facepalm]