Makro selling defective products online-refuses to refund

I bought a Dell Battery from Makro online. The battery arrived as a DOA or defective battery which had zero life and could not even turn the laptop on. I immediatey tried to log an online return but the system kept blocking me with errors and ways to prevent me from finalising the return request. I tried for 4 hours and called Makro support and was told speak to online sales and transfered me but nobody answered and call dropped after 10 mins. I tried again on second day and system worked to log return. A day later a notice comes up on my online profile stating the defective item is not returnable. I called Makro Support to report this bad service and wanted to take item to store for refund which the call center agent said was not possible and he would escalate to his manager after I submitted a photo of item and my details. No response received on when defective item will be fetched or what will the next step be. Exec from Makro to intervene and rectify or sell you business to someone who can deliver. Unhappy customer