Am in USA, the US/AF site does not allow booking flight originating in Vietnam.

The Vietnam AF site allows me to book, even has a promotion HAN-BKK RT all-in @ $144.01. But, when I pay, the charge is authorized on my CapitalOne card (my credit limit is reduced), I get a record locator, but no ticket is issued and I get a message "...due to the payment not having been validated online please contact the AirFrance call centre within 24 hours."

If I call the call center (US), I'm told they can't process the payment - I have to call Vietnam! They also tell me that they will only accept a credit card issued in Vietnam! Web support tells me that the only way someone in the US can make the reservation is by phone and pay the phone fee ($20) and not receive the promotion ($10off) making it more than 20% higher cost!
Is this correct?

For travel BKK-HAN, on the Thailand AF site, I'm able to use the same credit card and receive a ticket, EVEN THOUGH web support (in US) tells me that the Thailand site will only accept credit card issued in Thailand!
Then, they try and tell me that even though I have confirmation and e-ticket number, it may be canceled when they find out I used a US card on the Thailand site??!!

Does anyone here know the ins and outs of this crazy AF system?
Factors that may be involved here -
CapitalOne does not support Verified by Visa which AF tries to use.
On the Thailand site/ticket, the passenger & cardholder are the same.
On the Vietnam site/ticket attempt, the passenger & cardholder are different names.

Questions:
Will the Vietnam AF office (with limited hours) issue the ticket if I call them?
Would it work on Vietnam site if names matched without Verified by Visa?
Would it work on Vietnam site if names matched and a US card that supports verified by Visa?
Would it work on Vietnam site if names do not match and US card that supports verified by Visa?

Thank you, Merci bien, Aloha,
Richard