In case you missed it earlier in the thread, the mitigation here is that the OP was entitled to free travel - and indeed subsequently obtained a replacement pass. That might well count as an exceptional reason for settling this out of court with a warning. (It's not clear to what extent the prosecutor is aware of this yet.) Of course that doesn't detract from what the OP did. But secondly there is the question of how the prosecutor is translating what happened into that particular offence. While this is probably a routine matter for them, it is not obvious from the extracts from the paperwork, and they do need to spell this out so the OP can understand the precise offence. In essence this offence is one of not following instructions given to the OP and so for there to be a case to answer it is surely necessary to spell out precisely what those instructions were, when and how they were given, and in what way they were not followed. (This might involve references to case law.)