Question edited for clarity and Capitalization.
Contact them direct and ask where their closest service centre is. Rechargeable items only last so many charge cycles.
You may have the tuner too far away from the guitar or the batteries may be going flat. Check to make sure that there is nothing blocking the microphone hole and that there is no other noises in the area which could be affecting what the tuner is hearing
can you tell if there is a wire broken? if you know how to use a vom meter you can check to see if you have continuity if you don't then you have a wire problem & make sure that your battery is good.
