Does not work after five months of use

I received this product in mid-November 2013 and I have not used intensively (use for troubleshooting in conjunction with a desktop charger).
However, after 5 months of use, the battery is broken and the symptoms are diverse: either all LEDs flash abnormally, or a single line lights ... and recharging is no longer done. A branch of the AC unit does not solve the problem.
Thank you to Anker with customer service contact me to solve this problem.

Note:
- I am familiar with this Anker series because I also bought and received 12000mAh end model in October 2013: it still works as well. So I do not make a wrong diagnosis of the 6000mAh model, especially as the use is very simple.
- This article in good working order is really excellent and I remain hopeful that the VAS Anker (very good reputation) can find a solution. I'll let you know by an edict of this message.

Edit: As promised, I am sharing my contact with the VAS Anker. Well, this is the TOP of the TOP! SAV pro, responsive, friendly, listening, looking and offers specific solutions. In short, that happiness! I do not regret having bought this product which, in my opinion, this is what is done best in the field.