Good returned on 23/12/2015, still no refund!

I bought 2 dresses from Zando in December, however when they arrived they did not look like the pictures. I immediately logged a return and on 23/12/2015, a courier came to collect from me. I received a refund for one dress on 30/12/2015. I then queried why the other dress was not refunded and no one has provided me with feed back or acknowledged receipt of my emails. I would like my money to be refunded asap, this is really poor service.