I think i got robbed

I was previously bronze 2 but very far up almost bronze one, ive improved a lot since then and i won 7 out of ten games in my provos, but i only had gotten bronze 1. This doesnt make sense because my friend was in bronze 3 and then he won 7 out of ten and is in silver 4 now. I was on a seven game win streak and the last 2 games were filled with trollers because they couldn't get mid.