My sister's iPod 5G discharges while charging

Hello,

I have a problem with my sister's iPod 5G.

A few days ago, she told me that her iPod wouldn't charge anymore and the sign in the top right corner says the iPod is fully charged, also if it's not

so I tried fixing it. I have tried to restore the firmware several times, but nothing seemed to work. Also, I have googled this problem and many others have encountered the same problem but I haven't found any solution for this.

Is there any way to fix this problem without sending it to an apple store?