Westside Spares refusal to refund

I've never been exposed to such a shoddy and *********** service by Westside Spares, 187 Van Der Hoff Road in Pretoria West. I paid them R9500 for the car part which ultimately proved to be wrong though I gave them the sample of it. I returned the item and it took them a week to find me the other part which also was the wrong part. I finally had enough with them and returned their product and requested my money back. It has been weeks since they promised to refund me in 2 days and when i call them they always make excuses of their boss not being around. I will be taking legal action against this ppl and won't rest until I get my money back.