Applying for a single entry visa for China

Dear sir/madam,
I have a job related trip to Shanghai on the 8th of September for a period of 8 days.
Sadly I have to leave the 1st of september already to another Asian country.

I tried to make an appointment online with the Visa Department but sadly everything is full until the 16th of september. Could you please provide me an alternative on whats best to do.

I will also be from the 2nd of september in Seoul until the 8th of september and from there I will be travelling to Shanghai if I do get the visa for China.

Hope to hear from you soon.

Thank you and kind regards,

Suyat