Poor customer service

Good day

i recently bought a house from a developer called Homesforall in Randburg, been living in the house 7 months now, however some time towards Christmas 22 December if i am not mistaken, i had a problem with my solar geyser system, i then called the installer who is Nupower to come and sort out the problem

upon inspection the guy told me that the battery powering the system has been removed, and he confirmed that you can never be able to activate the unit on their system without the battery being plugged in to the geyser system, meaning that the battery was removed after it was installed and before i took occupation of the house, unfortunately this also caused a switch within the system to break

30 December of 2019 i wrote to John who is managing the development and their admin lady Marelieze,i sent them the invoice Nusolar issued to me, non of them responded, until 6 January when i sent a follow up email to Marelieze, only then she forwarded my email to Phumlani also in the JFS office, i still had to follow up with Phumlani to get a response, and he only responded on the 20th of January saying he will send the invoice to Nupower to get a detailed report, i have since been sending follow up emails with no response to date.