Troubleshoot. It's either your battery or the charging port. Does the USB stuff work? Can your pc "see" the device?
Not sure what device you have, can you swap put the battery and try in different device. Does a different battery charge in yours?
If it's non removable, take it to repair shop where they have the tools and instruments to quickly determine if it's the battery (=new battery), or the port (=new port)..