Is there any way that a player can change his nickname to a used one that is inactive for a long time? For example, i want to get rid of "_gt" from my nickname but "bird" is already used by someone who has been at a starting rank for a while.

My account was recently compromised by someone. During game play i got a server error message and had to rejoin. This happened a couple of times before i realized that my crystals were gone. I went into my garage and there were different items bought that i did not buy like the 100% multiplayer pass that as Generalissimo i don't need. About 80,000 crystals were wasted on different items. Obviously i quickly changed my password. The problem is that those crystals i was collecting are gone. Is there any way those useless purchases can be reversed and my crystals restored?