I was not refunded

I placed an order with Zando, it was a jeep shirt for my boyfriend's birthday. When the garment arrived it was too large. Unfortunately I couldn't give him the gift. I requested a return. Zando picked up this garment on 30th August. I have not received any information about the collection of the garment being successful or when do I receive a voucher so I can purchase something else. I've been emailing customer service and no one has responded. Is this the service of online stores? If so, this will be my first and last purchase online.