Hi

I am a Singaporean (holding a Singapore passport) and i intend to stay in China for 19 days (beyond the 15 days allowed under Visa exemption). I am currently in China and would like to know how i can extend my stay beyond 15 days. Can I

1) Apply for an extension or a Visa in GuangZhou or ShenZhen? If so, where should i go.

2) Leave for HK or Macau and re-enter within the same day? Do i get a fresh 15days from the date of re-entry?