The buyer would have brought the lable from Ebay if it was simply delivery which means if there is going to be a refund it will go to the buyer not the seller . Had the buyer marked it as collection he would have been given a qr code for you to scan on collrction which would releast his payment . I hope the buyer does not decide to open a non delivery even though he collected it as you have no proof it was collected or delivered . I am afraid i would have refused collection , or you could have arranged to cancel , relist for the buyer to complete the transaction correctly . This would not have been any different under the old postage system . If i am correct the buyer will not only recieve the refund you gave him plus the refund the refund for the unused label . I am surr if i am not correct someone will say so .