No refund and empty promises

I placed an order of multiple goods with online car parts and their system showed that they have Golf door handles on stock. However, the door handles were not included with my delivery. When I enquired, I was told that the handles are out of stock and I'll be refunded. Since July 2024, I have been writing emails and calling the store for my refund, and all I get are empty promises. It's now 8 months later and I still haven't got my refund.