Just cannot get it right

A week before Christmas 2015, I ordered an outdoor LED light from Groupon, which was advertised as being delivered before Christmas, needless to say it was not and when I got back from leave 8th Jaunuary 2016 there was a parcel from Groupon, I opened it when I got home and it was not only the wrong product (a desktop LED light) but the power cord that came with the product was not in the box. I logged an issue on the Groupon website, 12th of January I got a response 'Thank you very much for contacting Groupon Customer Service. We have received your query and a Groupon customer consultant will contact you within 2 working days.\ To date I have not heard another thing from Groupon, and apparently if I need it dealt with I will have to phone them. The last time I did that I was on hold for over 30 minutes, only to be fobbed off by a very disinterested customer service(?) person. So what exactly do I need to do to get Groupon to send me the product I paid for? <br> <br> "