Seller has informed me that they sent the incorrect item - I haven't picked it up from customs yet?

[egonrye]

Hello all!

I'm in a bit of a pickle.

I ordered a dress from USA to UK on July 6. I received the card in the post telling me that I needed to go to the post office to pay the customs charge (21 GBP) before I could receive the item - which is fine and expected. I was planning on paying the charge and picking up the item today.

However, the seller has now messaged me telling me that they sent me an incorrect item (trousers) and has sent my item to a different buyer. They're very keen to get the incorrect item they sent me to the correct buyer ASAP. 

My question is: how do I go about this? Do I pay the customs charge just to re-address the package and send back to the seller? The customs charge is 21 GBP, and shipping back to USA will be an additional ~15GBP. This is a lot of money out of my pocket that I'm not certain I'll get back. 

Also, I bought the dress to wear to a wedding next Thursday, and it seems unlikely that this will get resolved quickly enough for my dress to arrive on time - ergo, I will no longer require the dress. Can I just refuse the package and have it returned to sender, and request a refund? 

Sorry, I've never been in any type of situation like this and have no idea how to go about it correctly .. thanks everyone!

[green-night]

I could be wrong, but seems the best thing to do would be to inform your seller you are not going to be collecting the package and paying the custom related fees since it the incorrect item and that you would like a full refund.     The package should eventually be returned to the seller.