I'm Confused

okay, i'm just confused. I played my provisionals and i went 5-5. One of the losses was a double AFK game btw. After my provisionals, I got placed in Bronze V. I don't understand this placement because 1. 50% win rate should make you higher than the lowest tier 2. My friend went 2-8 and got silver. I am probably quitting LoL because of this, and I've spent at least 100 dollars on LoL. If there is a reasonable explanation for this please tell me. Last season i went 1-9 and got Bronze I and I'm just completely and utterly confused. I apologize for any grammar mistakes in this.