Unpaid refund, almost 1 month later

I placed an order on the 11th November 2024, I received my order with a missing item. They promised to refund me between 3 and 14 days and said the item was out of stock, yet I’m still waiting for a refund. I’ve been making a follow up with email without success. It’s almost a month now, without the item or the refund. A very disappointed customer, they have poor customer service and their agents are unreachable. They are always busy. Nonhlanhla Zwane