Terrible customer service

I bought a power bank off Groupon from Magic in the Box, it stopped working soon after I got it. I emailed Groupon and they gave me the email address of somebody at magic in the box. I got hold of Magic in the box via email and asked them if I could return it to get it replaced and they sent me a form to fill out which I did and they said they would pick it up. 6 months later still nothing and after multiple emails, and one or 2 replies apologising for terrible service....still nothing. It is now October and the last mail which I got was another 'sincere' apology about terrible service and how the person managing that account wasn't with them anymore. I rep**** on the same day and have again heard nothing.