Security's cameras

Good day I want to complain about this security company we put on 16 Dahua securuty cameras on our small holding by this company. The work they done is very sloppy and not very professional. He got his payment in cash with his promise he come back to look at thr results. The cameras and dvd player is from Dahau but all the other supplys is second hand and we pay for new ones. And after this weekend bad weather he took the splitter and the second monitor is also not working and he can't change the monitor because its second hand. And we pay for a new one. The power supply box is also not working and according to him its the weather all the cameras power supplys got water in because its not sealed tbe wires is also not sealed the work is very sloppy because he put workers on this with no experience on the wiring. After many attempts to phone him he swears and scream on us. And block us. We pay a lot of security and this is what we got. We very unhappy with this security company. Please help us.