Mahomed Midas Newcastle failure to refund items that were returned.

Invoice number 10MP6187 I purchased Shock absorber for Almera without the spring. The salesman assured me that I will get the spring at Spring specialists at Newcastle which I did not get. I had to look around to get the shock absorber with the spring which i got from Satar Motors and Auto centre. Then i decided to return the shock which was sealed and unused with the Strut Mounting also sealed. Zack and Yahya company directors told me about the return policy which was never explained to me when I was buying the items. The items are at the shop but they took my money and the items. What type of business is this? I need a refund of R885.