Dirette gas geyser installation problems

Not very knowledgeable with gas geyser installation problems experienced. Could not open the cold water while showering then gas geyser would switch off. Told me that is how it is supposed to work with gas geysers. You only shower with warm water. Had to adjust temperature on geyser too be able to shower. Leaked water on my ceiling. 4 weeks later didn’t advise when they will come and paint it. After service care bad.