(ii) Method: Through advertising messages (SMS, USSD, MMS), IVR calls, notifications on Viettel's Transaction Channel or other methods as prescribed by
(ii) Method: Through advertising messages (SMS, USSD, MMS), IVR calls, notifications on Viettel's Transaction Channel or other methods as prescribed by
(ii) Method: Through advertising messages (SMS, USSD, MMS), IVR calls, notifications on Viettel's Transaction Channel or other methods as prescribed by