My Beats Studio Wireless headphones suddenly stopped working.

I had my Beats By Dre headphones charging (you could see the lights indicating that they were fully charged) and when I unplugged them they would not turn on!!!! I've tried everything to get them to turn back on but nothing works. I tried taking them back to Best Buy but I don't have my receipt. I've had them about 3 months. Any suggestions on how to fix them?