Hello everyone.I am in China one month now, I am doing an internship here,in Changsha, Hunan province. I have an F type visa, 90 days duration, one-entry. I want to extend or renew my visa for another 3 or better 6 months. What should I do?Should I go to the local PSB or should I go to the Commissioer's office in Hong Kong?I read that they may ask for a return back ticket, but how can I book one since I dont know for how long I will stay after all?I really need accurate information coz I am very confused. I would appriciate any information or help.Thank you!