That's a fake, for sure.
Did it have the actual bandai logo on it?
I don't think that's legal. Although if you had looked closer, you may have noticed an imperfection in the logo, like the "I" was actually a "1" or the "B" in Bandai had an extra slash through it or something. Bootleggers often do that in order to avoid infringement by slightly altering the logo but keeping it just enough the same to trick someone into thinking it's genuine. I have a fake pokemon game that is like this - there is a cross through the "O" in Gameboy, which makes it so it's not a gameboy cartridge but a gamebøy cartridge in order to avoid copyright infringement. There is also a faux trademark symbol; instead of "TM" it says "TN" because Gamebøy is not actually trademarked, which means that advertising it as such could get them in trouble as well.
People are sneaky. :l