Dual Citizenship holder (HK citizen) marrying a Filipino here in Phippines.

Hi. I am currently in Philippines and will get married soon. Our church ask me to provide them a letter or a CERTIFICATE OF NO MARRIAGE since I am a dual citizenship holder. I tried calling China Embassy here in Manila to ask for more information but the telephone just kept ringing. I got no one to ask about this issue. I hope you'll get back to me and provide as more information as possible so I know I should be applying for this letter earlier or will it take some time to collect it? The wedding will be this coming May 2012.