Blizzard implemented a 15 games won requirement around Season 3 in order to receive end-of-season competitive rewards. If you did this however, then you might have experienced a bug. I’ve linked the competitive bugs megathread at the bottom of this post, which archives and documents almost every competitive bug. I’ve compiled a list of similar posts regarding similar bugs under: End-Of-Season Competitive Rank And Rewards. Please help in spreading the word about this megathread and other related threads, we must demand the Developers to give us the rewards we rightfully earned.