Undelivered online order and refund not processed

I ordered sneakers online on 29 November which is said to take 5 to 7 working days to be delivered. After 7 working days there was no communication at to date they have not delivered them. I cancelled the order and requested a refund and I received an email confirming that the refund is approved but to date I have not received my money and there's no communication. I made a follow up by email but they don't communicate at all. I need my money back please