Horrible service

I bought sneakers on Instagram from this account on the 18th of September 2022. The sneakers weren't delivered as agreed. I made contact with this guy via WhatsApp( ***) & Instagram and was told that aramix courier lost my package & he requested that I give him some time to sort it out.I agreed as this was not my first time using his services and he delivered before. Since then he never made contact as to update me as when I can expect them. Early October I requested my refund & he promised to pay me around the 6th of which he never did. Instead he blocked me on both WhatsApp and Instagram. Early this year I opened a new account on Instagram and again requested my refund and he ignored me. He only responded to me after I started posting about my experience about him. He made it clear that I won't get it since I posted "****" about him. I'm perplexed by his entitlement, who takes someone's money,fails to deliver, fails to refund and takes offence when the victim post about it. I mean it's been six months and still no sneakers no refund.