You must flash your phone with APAC-ANZ File System and CDA.
Vietnamese = VI
APAC-ANZ => en - nl - fr - de - ms - id - tl - th - vi - zs
Must use these files:
W595_R3EA037_MAIN_GENERIC_LD_RED52
W595_R3EA037_FS_APAC-ANZ_RED52
C905_1209-4765_R7A_GENERIC_APAC-ANZ (do not worry for C905 custpack, because W595 use the same custpack)
After flashing with A2uploader must update via SEUS to last version R3EG004.