In reply to yesbutnobutyesbut:
> But they will accept cards if you have your passport according to the OP.
deepsoup was referring to the postal order transaction, not the foreign currency transaction.
As it happens, though, the purchaser pays a fee when buying a postal order (minimum 50p, maximum £12.50) so I'd be surprised if the merchant's card transaction fees were the reason for refusing a debit card in payment.
http://www.postoffice.co.uk/postal-orders
I'm also a little surprised that pebbles seems to expect a counter clerk to understand the rationale behind
all the rules within which they have to work. I doubt they sell many postal orders these days so it's a pretty unusual transaction to have to know all the ins and outs of just in case a customer wants to question the rules - especially since the counter clerk can't do anything to change them.
Post edited at 11:31