[mothered]

so if i want to refund a gpu with batteries.  I insert the batteries in the gpu packaging (external packaging). 

You don't touch the GPU at all. The objective Is to claim that you've received a wrong Item In Its entirety. That Is, the storeperson picked and dispatched another Item, Instead of the one you've ordered.

When they request the return of the batteries, you send It exactly as It was received.