Poor service

My geyser stopped working on last Sunday. It is linked to an Telemetry device (smart wifi switch). SBI sent out two plumber but non are knowledgeable regarding this device. I still don't have hot water. The 3rd plumber won't come out as he doesn't do geyers anymore. No hot water. Family of 4. Cannot shower in hot water. No resolution from Standard Bank Insurance. I have been patient.