Bad customer service

I placed an order online for an item listed as "stock available". Was then advised that the stock was unavailable after payment went through. I opted for a refund. I was told it would take 7-14 working days to process the refund - I have still not received my refund after waiting the stipulated time. Tried to email - no response; tried to call - goes to voicemail and I even tried their online chat - no response. Makes me very concerned as to whether I will be receiving my refund. I made the mistake of doing a second order (after the first one fell through) and still waiting to hear if that will be delivered anytime soon.