Spoke to the ticket office this week - that was a system error and so they refunded me, only after they tried fobbing me off by saying "that game is closed off now".
If this happens to you, call up the ticket office and they will do the forward...
Adult to adult for the Liverpool FA cup game...I will probably call them up next week and query it.
Wouldn't surprise me if they introduce this new "admin fee" next season, even though we know it's an automated system online.