You are right, all things are dificult before they are easy . Next time, you will not waste any time when do the payment.
Pass the test is no problem, we are sure of it, becase we have export many kgs to your country this year, as you know we have buyers from your Thainland already.
Yes, we are far from the warehouse at Guangzhou, we are in the north part in China, but guangzhou located in the south area of China.
If you have a chance to visit guangzhou but not xi'an, we would like to try to go there to have a meet with you.