Urgently need help in fixing a document

Hello,

Can anyone help me on how can I have my marriage certificate and my son's birth certificate be fixed? I am a Filipino who married to a vietnamese guy and I live in Saigon right now.

For my marriage certificate, they did not put my middle name. They said it is ok and that I have to sign  it with my complete name as what is written on my passport. So I followed them and signed it which is very stupid on my part.

For my son's birth certificate. I gave birth to my son last November 2015. We registered him a month after but was called by the ministry of justice that my passport and the name on our marriage certificate are different persons and that I must get an affidavit saying the one on the marriage cert and on the passport are one person. So I get but I did not know that the law here in Vietnam states that the order of names are as follows: family name, middle name then the first name. Nobody corrected my husband and I about this. So on the the affidavit my name appears as what is proper in their law. Then the officer registered my son's birth. Still, they did not put his middle name which is supposed to be my family name before.

Now, I want everything to be fixed but I do not know what to do.

I hope somebody can help me. I am not good in Vietnamese that is why maybe I think they are doing this to get money from me in which I don't even have. My husband doesn't even know about their law in here.