No longer charges, whether on or off

No longer charges, whether on or off
My Logitech H800 wireless headset used to charge when on and in use, or when off and not in use, but now does neither. I have tried using USB from computer, from wall, changing different USB cables, everything I can think of. Where can I get a replacement battery pack for the Logitech H800 wireless headset?

ANSWERS:

You can also purchase the replacement battery directly from Logitech here but they ship only in the US.