Just to give you an update about this catering voucher issue, I was asked for more detailed information, which I supplied (they make you work for your refunds, do Ryanair). I gave a concise outline of the exact details of the voucher refusal and offered a couple of brief suggestions to help make it a smoother process in the future. In their response (it takes them about 10-14 days to turn around a response) I was offered a refund of €20 (instead of GBP10) to be processed to the card originally used. The only problem is, I'm not sure which one that was, because I used a different card to pay the extras. And the actual flight (not the extras) was paid for with my Lufthansa Miles & More credit card, a card which has now changed because I have been upgraded to Senator.