When a seller sends a postage label to return an item it's for a standrd 2kg weight.
If the item is heavier, then you need to contact eBay Customer Services, who will issue you the correct label, and charge this to the seller's account.
To Contact Customer Services it's a Live Chat, or you can select to speak and request a Call Back. Click on this link:
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
On weekdays lines open between 8 a.m. and 10 p.m.
On weekends they open between 9 a.m. and 6 p.m.
