On January 22nd, 2018, I was supposed to take my return flight home from Osaka, Japan with Air China. I bought my tickets through CheapOair. I was supposed to change flights in Shenzhen, China and fly to LA, then to Minnesota. When I arrived to the Air China ticket counter at Osaka Airport, I was told by the ladies at the counter that I could not take this flight because I don’t have Visa to China and the Shenzhen airport in China does not give visa on arrival.( not even the 24 hours transit visa) I explained to them that I was not aware of this because I had changed flights at the other airports in China such as Beijing and Shanghai airports in the past and they either issued transit visa on arrival or just didn’t require one. They told me to change the flight through Beijing but they said they cannot do anything at the ticket counter at the airport and give me the number to the call center of the airline. After many hours of calling and talking to many operators they just asked me to another tickets for flights which transit through Beijing. They asked me to buy tickets for the next day that will cost me about 1700 dollars. I am traveling on a tight budget and I had to buy new ticket to LA on Thursday the 25th for 425 dollars because the longer I stay and argue with them, the more I will spend on food and hotel, etc. I really need to get back to school and work as well. In my opinion, I should be informed by either the Air China or CheapOair that Shenzhen airport in China is very different from other major airports in China and that i needed to apply for visa beforehand. ( they obviously know since they didn’t even let me board the plane)I called CheapOair but they just tell me it was my fault and my fault alone the I didn’t check if I needed Visa to transit through Shenzhen, China. They said they will just sell me new sets of tickets and will not do anything for me. Now, I am still in Japan waiting for my flight on January 25th and still looking for flight from LAX to MSP.