Steps for turning metered data in Vietnam's cell into unlimited flat rate.
While in Vietnam, I kept eating all the credits in the pre-paid card due to data usage. Turns out there is a neat trick for stopping that. In essence, what you can do is to pay a flat rate of 70k points and have unlimited data for a month.
These are the steps for getting that:
Make sure you have at least 70k in the card. If not, buy some. You can see how many points you have by dialing *101#
Send the following text to the number 999: dk miu
Once you did that, you will no longer see your phone credits leaking away as you send emails, check facebook or do any other data communication using your cell phone!