Certificate of Visa Exemption subject to 90 day stay limit?

Hi all,

I am in District 1 in Ho Chi Minh City, Vietnam.  My plane is set to depart in 4 days!  (9/13)  It will be EXACTLY 90 days from the time I entered Vietnam.   Due to various reasons, I need to extend my VISA legally but do not wish to leave the country and return.   I have a 5 year Certificate of Visa Exemption booklet, that I understand to be a multiple entry 5 year one, as my parents were born in Vietnam. 

If, how can I quickly apply for an extension to stay past the 90 day limit, within 4 days and at the most cost effective and trustworthy way?    Through my travel agency/airline, I am able to change my return flight without issues or additional fees prior to takeoff.

Any help would be greatly appreciated!

Nevermind all, I found the definitive answer!

For U.S. citizens with a Certificate of Visa Exemption (validity of 5 years), the maximum stay PER TRIP to Vietnam is 180 days, NOT 90 days.   Furthermore, it can be extended in increments of 180 days. 

I hope this helps someone!

All VEC should be 180days use to be 90 days. But It would help if you look passport stamp, as that is what matters.

It has been 180 days for a few years now.  There's no extension per se because VEC expires after 5 years, full stop.  If you wish to stay longer, you'll have to apply for a new VEC.

When you re-enter after each trip, the 180 days start again on the date of your return.

Although it should show 180 days from the day you entered, better look at the stamp in your passport.  It could be they made an error.