The seller didn't pay the postage

[sochi217]

 The seller didn't pay the full postage. I have won the item on auction and paed agreed postage according to the sellers invoice. But later The pos offce sent me notification that the seller underpaid the postage and I had to pay additional money. S the postage for a tiny item was big. I would't buy it. The seller ignores all my messages and never responded. Thanks in advance for any advice.

[redwick1]

You should have contacted the seller first before paying.

If they did not send the extra postage and sort it out it would have been best to not collect it.

You could then have opened a not received dispute and got all your money back.

It is bad ebaying on the part of the seller 

it is also possible that the stamp fell off as it does happen

In that case the seller would have been able to claim it back off Royal Mail with the receipt of postage.

There is no way to force them to pay it now