maybe they see ur usage, they think ur like some kinda chinese farmer or something. Cos theres one time when alot of accounts get banned with no apparent reason when they wanted to filter out all the farmers and stuff..theres a customer service e-mail address for it. Cant remember it offhand though. try checking for it on the website. Their customer service is quite fast la. Around 2-3 days you'll get a feedback. so all the best in getting ur acc back