Disgusted

My son bought a pair of earbuds from Soundtech Vangate Mall. After 6 days he returned the item because it would not hold charge. On the receipt it says refund or exchange within 7days. My son came home with a repair slip. I went back on Saturday and spoke to the Manager or boss and hes adamant the item needs to be sent back to the supplier, clearly the staff cannot make decisions in that store. I insisted on my refund and he refused. I want my money back