Heat texh geyser warranty

I had a geyser installed, 27 Apri 2022l after my old geyser failed, my geyser was linked to solar tube already, the new geyser, says on its label : solar and pump compatible, however the element burned, plus thermostat, the company rep came and says because i had geyserwise thermostat installed, then the warrany is void. This is 3months after the new geyser was installed. I am angry.