GROUPON have not refunded my money

Early in December 2014 I contacted GROUPON about a purchase that had not gone through and was advised that I would get a refund for the items I had purchased. They requested my banking details which I immediately supp**** to them. A month later, after NUMEROUS emails and calls to the call centre, I am still yet to see a cent of my money. Quick to take your money but impossible to get it back! My advice to all is to stay away from this seller! This is not my first experience of this nature with GROUPON and the call centre is currently experiencing such high call volumes of complaints that it no longer takes any calls. So much for customer service!