CK Gate Auto dishonest

We hired CK Gate and Automation to replace cameras at our home. Kevin the owner and his technicians replaced the cameras on 16 May 2024. I paid for the work done as he insists on payment before they leave the premises. The cameras were not working properly so I called him to arrange for the cameras to tested and for the problem to be fixed. He quoted additional labour hours and for parts that were already included in the invoice. He was supposed to ensure that the cameras were working properly and this is what we paid him for. He became rude on WhatsApp and then apologised and sent his technicians back to my home. They confirmed that they believe that something was wrong with the actual cameras and promised to return with new cameras. This never happened. After several follow ups, Kevin decided to further escalate the cost of labour and parts. He is dishonest, his work is below standard and he deliberately sabotages the work undertaken to charge additional fees to fix the problem. He is rude and insulting. His work is sub standard. DO not use CH Gate and Auto. Kevin is extremely dishonest. Do not make an upfront payment.