Missing items in order, no refund, no communication.

I placed an order on 24 February. When the order arrived, a unit of 6 items were missing. Eventually I received a reply that it was out of stock. A month goes by, I inquired again (not very good at communication). Eventually received a reply on 24 March after various emails and chats, that "stock has been received and will be sent today'. 3 weeks later and I still haven't received it. I use the chat on the web again, because emails are not getting replies, hours later - "we will refund you'. And that's it. No 'what are your bank details etc. So here I sit without the catfood and no refund! No arrangement for the refund. I