I used Agribank ATM in Hanoi airport (international term. to your left once you exit customs) and in Hoi An (South of Danang) in July. I took out 3 mil VND each time on my Visa card (no issues) and no ATM fee charged by Agribank ^

I find a 50k ATM fee to be a rip off. Most VN banks charge 20k or 30k but some charge no fee at all.

The exhange rate is not set by the ATM bank in Vietnam but by your own bank (it is the latter the converts the VND amount into your home currency).