There could be a few things going on, if you don't mind narrowing down a few things:
The "brick" on the charger it self... There is a LED on it, Is this lighting up? Red? Green?
When you single press the button on the battery... What is lighting up? Amount of solid or flashing green lights
Batteries that are over 75% will not charge, It is some sort of safety built into the battery. This could also be why it will not take a charge since batteries are shipped with a charge. Per DJI Manual this is what they state "Connect the battery to the charger. If the current capacity of the battery is over 75%, you should power on
the battery to begin charging."