No delivery and No Refund of goods

I tried to buy coffee capsules on May 29, 2015 and made EFT payment. I got a notification that the good was dispatched. When I tried to verify it turned out my order was cancelled with no notification to me. I reverted to Groupon and they apologised and agreed to do a refund. This was supposed to be 3-5 working days. 2015/06/26 its more then 2 weeks later and still no refund. I advised them about it 3 days ago and checked again and no refund.