G'day,
Did you buy a cheap phone from China? They usually don't support Band 28…
What is life without the band 28 (700MHz) in Sydney and NSW?
Is it OK to live without it, i.e. will you be dropping out of calls when moving around, going indoors, driving etc.
Cheers
VoLTE (calls on 4G) is usually only supported on carrier ROMs anyway. Most calls still go through 3G. B28 is a LTE band, which won't affect calls unless you use VoLTE.
Basically you end up with slower data in some areas.