CellC Mobile operator in South Africa

3rd Largest, after Vodacom and MTN
Offers Wifi Calling, allowing supported phones to log onto the mobile network via Wifi, thus facilitatinig free roaming worldwide.
2017 Ported my Vodacom number to CellC and got a supported Wifi Roaming handset.
2018 Tried to use the CellC sim in a Note3.
- Kept on getting error "Network not available"
- Visited the CellC sales office in Johannesburg, was informed that because the sim works in the CellC handset my Note3 must be faulty.
- Updated the firmware on the Note3 (I'm sure it works, used it until the sim change) still no luck
- Searched the internet, found a couple of similar complaints but no resolution.