They damaged my geyser

On the 19th November while I was at work I received a hysterical call from my housekeeper to say the geyser was overflowing. I thought it had burst. I called my insurance AON. They recommended A call away electrical. A technician called M.Jacobs came. According to my housekeeper the water has stopped flowing over by the time he got there. He then assessed and decided that the problem was the thermostat and the valve. I then agreed that he can fix these 2 things. The next day the geyser was on it tripped electricity. Eversince then we haven't been able to use that geyser. I have SMS and emailed A call away and they have not come back to assess what kind of damage they caused. My geyser was working fine until their rechnician fixed a damage that was not there.