Bad service

Power mods in Alberton North installed a after market computer system to my car. The instalation was incoplete as the coputer was laying on the floor there where wirres that where not conected. Thye had called me to collect the car. When i got there the car dit not start with the key and the price was given to me before i took the car in 1.500 rand they told me to pay 2000 rand before i take the car. But the work was not complete.