Hi, I've been using Sentry BT200 bluetooth headphones for about two months, and while I was in the grocery store listening to music, it suddenly stopped playing, and for a moment I thought my headphones had died, but I didn't hear "Low Battery" play. Upon further inspection, the blue LED light was still flashing and my phone was no longer connected to the headphones. I tried turning it off by holding the power button but nothing happened and the light kept flashing. I can't get it to turn off, and it won't connect to any of my devices. Any suggestions?