Hi, the only way a payment can be returned from a bank transfer payment, is by the person who received the payment doing a BT to return it. I suppose in theory the buyer's bank could intervene but that would be very unlikely. In my experience it is hard enough trying to get the banks to correct their own mistakes, without trying to get them involved in things were they have no responsibility for the error.
I know you are not British but I would suggest that you have a look at this site, if you go to the site map and click on the payment options button that will give you quite good information. wwww.ukauctionhelp.co.uk