Just over a month ago I travelled on Avanti to Birmingham International on an off-peak return plus SeatFrog first class upgrade; the latter cost £38. No first class catering was provided on board due to "staff shortages", so in effect I received the Standard Premium service. The train manager would not give me any evidence of the lack of catering but said it was logged and to write in for a refund. I contacted SeatFrog asking for a refund of £23 being the difference between what I paid and the onboard upgrade price for the journey made. They fobbed me off to Avanti who after a bit of back and forth have today emailed me to say they are going to refund the full £38 by cheque. So a good result.