Stainless steel urn rusting in less than 3 months of use.

I bought a ****sware Stainless steel Urn at Makro and in less than 3 months the urn is tasting. I took to the retailer yesterday and to my surprise they told me that I must wait for the manufacturer to find out the cause of the rusting and they will contact me back. What I don't get is I bought a stainless steel urn which means it's not supposed to rust and in less than 3 months it is rusting,from what I know I must get my full refund because this is less than 6 months of purchase. So why must I wait for the manufacturer when I bought the product from Makro? Makro must deal with its manufacturer while I get my full refund. This is unacceptable at all.