beats solo right speaker failure

I purchased two Beats Solo from an authorized retailer for Christmas 2014 for my teenagers. The right side speaker in the headphones stopped playing any sound in April 2015. We tried all the suggested fixes such as plugging into a different device, making sure the cables are plugged in correctly, balance config., buying a replacement cable and none of them work. 3 weeks later, the second pair developed the same problem with the right speaker. Is this a flaw with this product? At this price I would have expected them to be problem free for more than 4-5 months. I am very disappointed. Please let me know if you have any suggestions or if this is to be expected. Thanks.