Thank you for giving advises, everyone. I have ascertained the cause to be hacking. In my garage, there are many unknown turrets that I would not buy. Perhaps someone logged my account and bought them, to exhaust my crystals. I decided to change my password and scrap this　account. Thanks a lot.

I was playing Tanki at an "opposition" map, for a long time, about 3 hours. Near the end of the battle, a connection error had occurred, and i was　obliged to exit the room. After the next login, the number of my crystal stock have been ZERO. If my memory is　accurate, i had about 3100 crystals, but my all crystals have lost for a moment!! Of course, among that, i had not done any operation. What's a terrible story?? I hope the Tanki managers to restore my crystals. Perhaps the log of my profile infomation isn't left in the server, but i dont　want to despair continuing tanki, due to one connection error.

vsem privet!! i drew the traditional art of my country!!