Would not exchange a product

I have bought a pen from CNA. I asked the shop assistant if it was plastic or steel. She said if she looks at the price it should be steel. Upon purchasing it I opened it at the counter. It was plastic. I said that I rather then exchange it for an even more expensive one. The assistant manager refuse to exchange it and said I must lay a complaint. I did Ref ********** 0700/GO. No response as they promise will be within 48 hours. I urge other consumers to boycott EDCON GROUP OF COMPANIES and rather deal with independent suppliers which staff is more willing to assist. I now sit with a pen that I would not use and can just as well throw it away. The corporate companies think they is untouchable. Let's show them this festive season they are not.