Ranked Needs Fixing

How in the world is it fair that u can win 80% of your placements, do good in them too, lose 1 due to teammate afk, and go down 3 divisions? i was silver 5 at the end of last season. i have gotten alot better since the end and was hoping to go to high silver or even gold. but i go down 3 divisions? what the hell kind of sense is that? i could understand, " we would like people to work to climb devisions." ok i get that, but if u want to do that u might as well just keep everyone at the same rank that they were last season. I really want to get a border cause apparently silver 5 doesnt count as silver cause i didnt get a border. and i was hoping to get at least a silver one if not gold. but if i have to work to get to the same spot as last year then there's no point to even play ranked. plz fix this riot i love this game and dont want to stop, but if i have to work to get to the same spot then ill have to stop playing. and i know im not the only one who feels this way