Failed to pay ThaiRailTicket using BIG Card

This is frustrating. I never encounter this problem using my previous credit cards
to make online payment-either domestic or international purchase.

Here is what I encountered then I try to make purchase to buy 8 tickets from ThaiRailTicket for my Thai-Laos trip in November.

Option #1: Paying by Choosing Credit Card Payment (via Bangkok Bank).

Enter the normal details as usual:

 Enter the password as usual also. Verification successful.
 Erk?! Transaction Declined?

After I post the question to ThaiRailTicket Facebook, they replied this:

Waaa. Malaysia is a high risk country until it is rejected? Hmm.. So i tried Option #2 as suggested.

Option #2: Paying by Choosing Debit Card Payment (via Kasikorn Bank).
Enter details as usual and confirmed:

Again. FAILED! If I click "Continue", it says redirect to Merchant website. but that failed and bring back to ThaiRailTicket website with the message "reservation canceled.

Then I tried the link to Verified by Visa: 
My BIG Card not eligible? WTH?

This is very frustrating. Now I'm waiting an answer from either BIG Card or ThaiRailTicket to explain what else I should do. Coz I dunno the problem because of BIG card or Thailand banks or ThaiRailTicket.

 If still unsolved, then I need to try using my Visa Debit Maybank or Mastercard Debit CIMB.  I seriously doubt this is a browser issue.

If all fail, I really dont know how else to make online payment for my backpackers group. *Sigh*