I want Checkers to honor the warranty on a product bought at Checkers

If I buy a product from one of your stores and the product is listed on your till slip then I expect Checkers and Checkers Hyper to provide me with a refund in the event that the product is defect. So why is this not the case when it comes to items bought from the Verimark section? And how can Verimark make up their own terms and conditions when these terms and conditions do not appear on the till slip?