How can I get an visa for China?

I'm afraid you will be not able to get a China visa in South Korea even if you apply for the visa at present, since non-Korean applicants in South Korea who want to apply for visas to China, must provide alien registration card in South Korea with at least 6 months remaining validity. I advise you try to contact China Travel Service Hk Limited to see whether they may help you to get an China visa. I used to use their service, and find that they are very capable of helping to get China visas. Their hotline is 852 2998 7888