It is possible that you just plane got a junk battery.
I am sorry but I will be blunt. You bought a cheap throw away airplane. One thing in common with these are inconsistant quality.
I was in the same boat as you with one I bought when I first started out. The battery lasted all of one charge.
Try charging it again but you may end up contacting the company for a replacement.
UMM one last thing, are you sure it is the battery? The ESC on alot of electrics won't arm unless your throttle stick AND trim switch are both all the way to their lowest setting when you plug the battery in (safety feature)