Renault Tyger valley poor service

Bought an Aircooler/resiter-fuse from them, Renault Tyger Valley had it fitted by Renault Parrow , after less than 100km it stopped working. They come up with all stories but when I took it to a Auto electrical the auto electrician told me the part was faulty. They tested the fan, the aircooler etc. Renault want R5800 to fix it and R1500 to put on a computer. Why put it on a computer when i told them what was wrong, Theyn kept it for 4 days and told me the aircon was not working. Autolec charged me R658,00 for taking the air cooler and fan out, bench tested it and repaired it.