Shoddy Geyser Installation

The geyser was installed on the 10th April and did not work correctly, the water pressure was faulty. I called a couple of days later and was told to allow the geyser a couple more days to settle. I called again to report that the problem was not sorted and three days later he came and did a small adjustment and told me to give it a couple more days, this did not help. He then came and found that the hot water pipe and the pressure outlet had not been installed correctly, they had been transposed. This was then rectified but the problem still persisted. His assistant was then contacted on Sunday evening and a promise was made to rectify the problem at 10am the next morning, no one pitched so I called at 15:30 to follow up. Lenny had no idea of the arrangement and became hostile when I insisted that this was an urgent matter, he has now arranged to come on Tuesday at 15:00, lets hope this is the last time he needs to do any repairs as this has been an on-going issue for more that three weeks. What type of plumber is he if he is not even able to install a geyser correctly???