I sent a parcel and used postage label as offered by eBay but buyer was charged the extra postage. As the parcel was larger though weight the same . The buyer wants me to re pay postage payment to him directly but when I sent the item eBay said if incorrect I would be charged the extra via eBay , which I was fine with. But I need to make sure I havent been charged the extra and do I also pay the extra charge back to the buyer ?