bad service I got at edgars maponya

I bought items on promotions at edgars jabulani then I went to exchange this items at edgars maponya,helped by a teller called promise after me and my wife waited for so long to be helped. The manager grace told me that I can't exchange cause she will never over-write a price,I'm ****ed off because that means if I buy items there I'm forced not to exchange them because they where on promo that's the most digusting I've aver heard from edgars. I will never shop there anymore. They treated me as I'm nothing,they only love us when we spend money. Sies!!