Groupon taking far too long to process my refund

On the 19th of March 2015, I ordered a patio set with groupon which was delivered to me on the 2th of March 2015. On receipt of the patio set, I discovered its too small for my space and decided to take it back to groupon for a refund. I called groupon and they processed a return receipt for me and the goods were collected by their courier for return. The goods were received by groupon on the 13th of April and on enquiry about the status of the refund I was advised that it will take about 7 working days for the goods to be checked for quality purposes and then process the refund. I kept on calling to follow up, on the 17th of April I was informed by Guido that my name is on the list of the refunds to be processed and it would appear on my account in 3 to 5 working days. Today the 24th of April, my money is not reflecting as yet.On enquiry with them I was told that the goods have not been inspected yet when i was told my refund is being processed last week already. I'm wondering why is it so easy for groupon to debit my credit card on purchase of the goods and yet so difficult for them to refund!!!