Incompetence, delayed deliveries, wrong items delivered, inability to process refund

Zando has extremely poor customer service. I do not recommend ordering anything from Zando if it can be purchased from any other website. I ordered a pair of shoes in size 5/6. They arrived days after the indicated maximum delivery date. The shoes were a size 8/9, despite the fact that I had ordered a size 5/6 and were huge. I was unable to process a refund/return request as the website and app had not yet updated my order. I sent an email and received no response, however my refund request was thereafter remotely updated without my input, with the wrong collection address. My calls to the call centre to resolve this took approximately 45 minutes, charged at premium call rates, because I was placed on hold for so long. The call centre updated the refund collection address. I assume my item was collected from my building's reception, however I don't know if this is the case as I received no notification and the website has now been down for about two weeks. I therefore cannot track my refund collection/processing. I have not received a refund. This is tantamount to theft and I don't know what to do to get my money back.