Promise never kept

Bought a gaming chair online. Waited a year and it never got delivered. They said the item was out of stock. Checked their website and the item was available for more money. After I escalated it a couple 9f times and demanded my product the website got updated. Another year later and I still don't have the item or my money back. I contacted them once a month and all I hear is that they have escalated the matter. Their customer service is the worst - there so not even an appology anymore. At the beginning they promised a voucher for. the long waiting time. I had to follow up 5 times before it came.through. They still have my money for the chair and I still ask every month for my refund.. they can't do anything - useless :/