Hi,
Does the old battery indicate that is is charging when you insert it?
If it does then perhaps your new battery either has dirty contacts (are they bright and shiny?) or it is faulty.
If not have you tried connecting the camera to another compatible charging source to prove whether the charger is at fault? Try a different cable as well if you have one.
If it still won't charge try placing a thin shim of paper shaped like the base of the battery between the battery cover and the battery. Hopefully this will exert a bit of pressure on the battery when the cover is closed so that it has a better connection with the battery contacts in the camera. Do not make it too thick, (<1mm) you still want the cover to close properly.