I've checked their T&C and they don't mention delivery charges directly, however they do in a round about way. They say that orders returned under distance selling rules get a refund for the goods, the implication I'd take from that is that delivery charges aren't refunded.
"If you refuse the delivery of your order for reasons under the Distance Selling regulations or you fail to take delivery because you have cancelled your contract under the Distance Selling Regulations, ****** will refund or re-credit you within 30 days for any sum that has been paid by you or debited from your credit card for the goods."
To be honest though I don't think there's any merit in trawling through the T&C, since it's clear their interpretation is the one that counts. I think they will refuse to refund me delivery and it'll go to a Paypal decision.