Kotwal spares Midrand Bad service

I bought 3 coils packs at Kotwal Spares in Midrand after changing it my car still had the same problem,mind was like since the coils are new the car might have some other issues I took my car fr diagnosis early May so that I can find the real problem or fault ,it was detected that COIL packs are fault video was taken with their coil and other coils to show that their coils packs got problem but they refuse to assist me to take back their faulty coils packs telling me I need print out it's not everyone who does diagnostic that can have print out ,even though the saw the video still they doesn't want to exchange or refund me ,Kotwal got bad service they don't have customer care. Before that I called the manager there to explain the situation he said I can bring them back ,but when I get there he refused to help me telling me about the supplier.