Giving a refund plus return postage cost

[cake*smash]

I need to give a customer a refund plus return postage cost through PayPal and PayPal doesn't accept the extra amount for extra postage on top

[norseway53]

You must only refund through a case or cancellation if you want your final value fees back and don't want a defect (strike) on your selling account.  Did your customer open a case?  If not then ask them to do so.