I'm not sure how this forum works but I have moderated others in the past. When facing stuff like this we could ban by name or by IP address and also blocks of IP's that covered an entire region. Captcha on login is great idea to stop spam bots.
Ok, a heads up. In the exchange shop it says you can use all forms of trade with the shard but when you get it you cannot sell it. It is bound to you. Other items like the Halo Box plainly say you cannot trade it but the shards trick you.