First of all I have to apologise for any inconvenience it has caused you.
We have no any idea at all of the Vietnamese Custom requirement. Then we have sent you the draft of the shipping documents to get the final approval from you before shipping the cargo.
We have experienced of shipping the goods to Vietnam many times. Some of our customers, the shipping documents, we did the same as sending to you and we got no any claim from them.
Anyway if you need any help from us please kindly let me know.
P.S. We have also experienced to ship to Taikisha Hanoi.
They gave us the detail of shipping instruction beforehand. I think you should ask them for help.