I’m the same as flyingmonkeycorps – the original listing was at +3.95 postage, which makes sense as that’s what the OP also was suggesting ‘just over £20’.
If I look in my ebay history, and click the item, it’s still showing as 3.95 postage, but also indicating that the seller has updated the listing…
click on the updated listing and it’s free postage.
Is this what other folk who are claiming the postage back are seeing?