Mulitple emails and calls but no response

I ordered a product from groupon just before Christmas. It was an watch that could track your calories, steps, sleep etc. I purposefully purchased this to take with on our holiday. It arrived in time and i was thrilled. Two days into my holiday the watch stopped working, and i was u able to use it again. When i returned from holiday I contacted groupon. I finally got hold of someone who briefly assisted me over email by sending me a return form. Since then i have not heard from him. I have sent countless emails, have spent hours on the phone trying to get someone to help me but no luck. No one has contacted me or rep**** to me. I am waiting over a month now- feeling hopeless. I have never recieved such bad customer service. Who ignores someone via email, especially after initially making contact regarding my return. I dont know what to do anymore? I am sitting with an expensive, factory fault broken watch and no one is helping me