It's hopeless.... It seems like they don't know what VoLTE is.....
In a forum I've seen this photo
https://i.gyazo.com/9bfc013d22750e6cc675bbb041351ab5.png
In his B618, which is Telkom-branded, there is this new firmware upgrade, since December 2018.
My B618 is not branded, and I still don't have the upgrade. It says that it's already up to date, but I don't have VoLTE management, and, if I try to force-enable it, by calling the IMS in a new APN, it tells me that I can't do such action, because it's reserved for VoLTE....
So it's confirmed that my B618 HAS VoLTE... BUT WHY I CAN'T MANAGE IT???? IT'S ALWAYS OFF!
I need to call without downgrade in 3G, but I can't, since I can't enable VoLTE!!!
Can someone PLEASE help me?