Dischem Misleading Sale prices

Dischem is misleading their customers. They have 20% discount adds flying above sales items. You as customer purchase the product not knowing that the price on the shelf us the discounted price. When I confronted the Manager at Kenilworth Centre branch they told me that they are making it easy fir the customer so that you don't have to work out the 20% discount. I told them it is misleading as you expect to get a 20% discount on the shelf price as there is no original price on the shelf. The response was that is how head office wants it. Totally misleading the customers, thinking they getting a discounted price at till.