korean motors boksburg

last november 2020 I bought upper ball joints for hyndai sonata at korean spares in boksburg and they were intalled december the same year, but 2 months later i found out that the parts were faulty,we took them out send back to the spares they refused to refund me,telling it is their warehose policy which I did not understand because are bought the parts from them, I also have the video of the faulty parts, please help me get my refund