Have you tried taking a screen print of the error message you got from the Ryanair site? Might back up your conversation tomorrow. (Though I wouldn't bank on it - the Ryanair desk crew seem to operate from a fixed script).
If it's of any use, there are internet terminals in the departures hall in Dublin airport with printers attached if you wanted to try again in the airport. I think they're coin-operated, and not sure how much they cost, but it's definitely far less than €40 each!