No Return, No Refund Policy

I purchased a wireless charger at Vodacom’s ORT store on 16 Dec. Charger and phone got extremely hot when charging and phone did not charge. I purchased a new charger that worked fine. On 19 Dec I returned charger to same Vodacom ORT store and was refused a refund and return. I understand that a consumer can return a product within 7 days of purchase for a full refund no questions asked. I’m now stuck with a broken charger! How do I take this further as I’m feeling very unfairly treated as a customer?