No delivery - 4 months later!

I placed an order through Groupon for Canvas prints in December 2014. In January, I was told they had not received the pictures I wanted used. Pictures were sent and by 28 February - still nothing. I was promised then that my order would be moved to priority. It is now 07 April, they are no longer replying to my mails and I have received NOTHING from them. Absolutely shocking service.