Wrong painting delivered. Exchange or refund needed

My husband ordered a painting online and wrong item was delivered in February. Its been 4 weeks and wrong item hasnt been collected and we havent received our refund. Can someone attend to this issue. It was our 1st time buying from Leroy and with this kind of bad service. We will never purchase anything from Leroy again. We 1st wanted an exchange on the wrong item because no one is attending to our case we need for this thing to be collected and our money refunded. Order no: *** and case no: 856793