UK buyer ask to return a custom printed cards

[robianprint]

we run a print shop in ebay.com.au.
An UK buyer came cross to buy our plastic business cards.
we got his file, create a proof to show him and printed and express post to him.
the fee is $85 + express postage $50

After 10 days buyer received the card and open a refund said item not descripted as it is not good enough in colour.
we show the proof he approval and his origianl file and finish product. it is exace the same.

we told him this is custom made it is pointeless to return to us. we have 100% feedback and have been sold over 30 orders to other buyers

Anyone can help this case. Buyer can use any reason said item is NOT described and return custom printed cards. The worst is we have to pay for the return postage or we lose $135 and buyer get the cards for free.

our ID robianprint

buyer ID worre-richc