Zivame - Refund of returned items not processed

Refund of returned items which was returned to seller on **th may is not processed yet. I mailed their customer support team about ** times showing them the proof of everything shared by the courier partners(delhivery) that the items got delivered to zivame. But they kept on saying that they didn't received any updated info. And now they are not replying to mails also. My husband approached zivame management team on lindn and twitter too but they don't have shame at all. We have connected with the ceo also, still not a little courtesy from their side. These so called big companies make fool of their customers.