What is up with the Flex Queue placements!?!?!?!?

Ok, so initially I was upset that all that was available was Flex Queue, but I figured what the hell, I wanna see how it is. And I enjoyed it for the most part. What bothered me is this: I was placed against Silver and Gold players, with some of the matches having Plat and Diamond players in them. Now I wont say I did AMAZING or anything, but I feel for being in Silver against much more experienced players, that I did fairly well. And when I finished my ten games( and I only think I won 5 out of 10) I was placed in B3. And after all that aggravation, I logged in the next day, played a ranked and WON and was told I was placed in B4.... I just want an explanation to help this make some, if any, sense to me. The fight out of Bronze is insane, it really is. When I got into Silver, it marked a new chapter for me. And now I get slapped in the face, not once, but TWICE, with however it is they have the Flex system set up.