My money is good enough now where is my order

As a past Groupon supplier I knew how stringend they were in ensuring that the company they were dealing with would meet a set standard but that was then and this is now. Ordered 2 framed prints from Print On Line and Groupon. <br> <br> One voucher was retuned after expiry date making it look as if I never used it, the second was processed and never delivered. Groupon's take on the problem is to suggest that I contact the seller. The very seller that they can not get hold of either. <br> <br> I have the proof that both vouchers were claimed in the form of delivery fees deducted from my credit cards BUT do not be concerned because Groupon does not care. Although I have made online purchases with Groupon since then it has been with reluctance and fear. <br> <br> If they can not secure your order or refund your money, what recourse does one have<br>