Have you tried using a different charging cable? Also to unpair a device to connect another press both the + and - buttons at the same time for 3 seconds. In order to power in/off make sure your pressing the multi use button which is the middle button on the controller
If your still having issues send firstname.lastname@example.org a message and let them know of the problems you are experiencing. Also supply the troubleshooting steps you have taken, order number and serial number of the headphones.