For charging using a laptop:

Using a micro cable connect the speaker to the USB port on the laptop/computer

Make sure that your PC/laptop is turned ON and not in sleep / hibernate mode

If it still doesn't work try with a different USB port on your laptop/computer just to be sure whether an issue exists with your USB port

For charging using an adapter: 

Using a micro cable connect the speaker to the USB port on the adapter

Make sure that the wall socket is functioning properly and not loose or damaged

If it still doesn't work try to charge from a different wall socket

If the speaker still doesn't charge try with a different USB cable that is suitable to connect to your headset charging port just to clarify whether the issue is from your current charging cable.