LMFAO! That's why this game is somewhat of a scam. Konami teases their players to try to get them continue grinding/playing and spend money at the shop.
I have been playing this game for a while and I have never seen THAT before. Honestly, this game isn't even much of a scam. I have completed almost every event thus far, cards and all, and I've only spent money in order to get the mats and sleeves that they give for sales. This was just extremely bad luck.
I’ve gotten more prismatic drops from level 30 Zane than level 40. Every time duel level 40 all he drops are rare chests and card packs. It’s really ridiculous how stingy Konami is even with the f2p events like this