Please follow the below steps if the client mentions that the device isn't charging.
Check if the charger is working with any other device
Ask client to remove the battery, keep it aside for 30 minutes and use it again in the device
Advise client to share a video of the issue to check if there are any damages to the charging port (In this video, client must connect the charger to the device and switch it on and display the screen)
Please reach out to the technical team in case of any queries/issues.