I bought some stuff from China on AliExpress that was about £7. HMRC assessed it as worth £28 and charged VAT and Royal Mail added a further £7.50 forwarding fee. I was required to pay all fees to RM before RM would deliver. I enquired what would happen if the money was not paid and they said it would be returned to sender in 28 days. So that was what happened. I got a refund on the original order.

I then reordered and it came straight through. (It was electrical sockets which were unshuttered with flimsy contacts, so unsafe and I did not use them in the end).