Pre Order Price change

I ordered some archery equipment from a UK retailer in October on preorder. It took a lot longer to arrive than anticipated. They quoted November it arrived today.
Because the item was sent to them from the States and the exchange rate altered, they have charged me £15 extra. I have been told that this isn’t legal. Would anyone agree / disagree.
I have to go down there tomorrow because they have cocked the order up anyway. So I would very much like to stuff as much sh** as poss up their chuffs

I think the answer is potentially both, it depends on exactly how the items have been sold to you. Whether they said it would cost x, whether it was written down signed, whether you asked for it to be sold on your terms or theirs. whether payment had been made or merely a price quoted.

There is a contract but it depends on the terms and conditions as to who accepted what and on what terms, ignorance on your part of their terms is no defence if it is deemed that you accepted their terms.

Your best bet is to have a chat with trading standards just to confirm what your options are.