I travelled to AUS is Aug and then backed to Vietnam after 10 days. I bought a prepaid sim and use my credit carc to top up. I do not know why when i was back to Việt Nam, Optis is still charging me everyweek. Please remove it ASAP.
Sorry to hear about your situation here, @Billyvietnam. If you reach out to the Billing team on Live Chat, we can investigate this and make the necessary adjustments. We won't be able to organise a call back directly through here unfortunately.