Extension of Visa for more than 14 days

Dear Sir

I am here in Shenzhen for business trip. Apprently our client will be jpining us for sourcing in Shanghai and Yiwu for a duration of 18 days.

I would like to check by chance if your kind office can assist in issuing a letter for extension of our next Visa
for more than 14 days ? We will not be in time to perform re- entry within the 14 days entry period during our
trip in Shanghai.

Hope you can help and let us know if any option we can have this solve.

Yours sincerely.
Andrew Lim
Tel: 13794472819