Red-E 8 Pin Lightning Cable (Iphone 5 charger)

I bought a Red-E 8 Pin Lightning Cable (Iphone 5 charger) at your store. The product comes with a lifetime guarantee. I have subsequently exchanged the product 4 times due to the cable being faulty. The cable seems to work for only a few days where after it starts giving problems (not charging at all). Really disappointed in Cape Union Mart, as you would expect that you stock quality products, hence the reason I shop there. I informed the store of this fault, where after they still continued to stock this item.