If it's such a big deal that he "took your money", why not just read the entire terms of agreement or EULA you get when you buy a key or open up Blockland and check to see if there really is a right for him to take your money if you abuse the game and other players?
The same applies to any other game service. If you paid a month for World of Warcraft, got caught hacking the game's servers and were banned permanently from playing, crying to Blizzard asking for $14.99 back for that one month payment isn't exactly going to give you back $14.99 because you agreed to the EULA stating somewhere probably that if you ruin the game for others your right to play the game is removed. Same applies to Steam and if you hack Steam servers to intentionally ruin games for others, VAC banned players don't get their money back. That's the price they pay.
It's an efficient way of enforcing order in games. "If you play mean and ruin the fun for others you won't be able to play unless you pay again."
Unless you actually went through any / whereever terms of agreement / terms of service / end-user's license agreement for Blockland and actually found no evidence of Badspot stating that he has the right to revoke your privilege to play the game, you probably can sue him or something else. Seriously, telling us about how he "stole money from you" isn't exactly going to turn our minds around so we show up in court supporting you or something.