3 weeks later, no refund processed and no feedback

I returned an online order 3 weeks ago which they acknowledged they received but till today, I haven't been refunded. Calls are ignored and just ring, when they do answer they make false promises and still not attend to queries. Very poor customer service, I really regret spending my money on a business that doesn't care about its customers. They even ignore messages on their whatsapp line. I WANT MY MONEY BACK