Clothes of Poor Quality

Over the weekend I bought a pair of David Jones pants and only wore them today...after work to my surprise the material was very weak and it's as if its about to tear. My intention was not to return the pants hence i threw away the price tag. I feel like its a ******* and unfair if i have paid for something I'm not sure I'll ever wear. I would like to exchange it for something else but i know I'll be turned away at one of your stores but I'm not happy with this at all as i wasnt expecting it from your store. I still have the slip