Monogram Hub recieved wrong monogram necklace, company will not email me back to replace New york Internet

I ordered a necklace for a 16th birthday on September 19, 2014.  I emailed with a customer rep to confirm the monogram would be in the correct order.  When I recieved the item three weeks later, the monogram was not correct.  I have tried emailing them three times and calling and have not recieved an email or call back.  I am out $150 and three weeks late on a sweet 16 birthday present.  The lack of customer service is horrible and i am contacting groupon as well because they had a deal with this company.