Double and triple check what you purchase from the Vodacom Shop in Woodlands

I bought a Samsung A12 from the Vodacom Shop Woodlands which needed to be a dual sim. I showed her my son's phone which he bought at Edgars but MTN locked for a year. The sales lady assured me twice it was a dual sim but when I started the phone, it was a single sim. The Manageress, Joanne, made myself and my son-in-law out as ***** in the shop even though she admitted the sales lady asked her if it was a dual sim in the back. Now they refuse to swap it for a dual sim or give my money back. I have raised a complaint with Vodacom but no answer. I took it back within the 7 day period. Absolutely shocking service with a very rude manageress. She said the box was opened but the sales lady fitted the screen protector in shop. She also said she would phone me but did not