You really should get in touch with the media. Radio 5, BBC website, Times Radio, local MP, your local paper…. The iron is hot at the moment with unfair penalties - strike now. You have been fined nearly £200 for the offence of “having bought tickets online before travelling”. Surely headline stuff.
It’s a bit like being stoped by a policeman whilst driving in a built up area, being asked how fast you were going, replying “45 km/h officer” and him issuing a fine “because you should have replied in imperial measurements”.
If you had had the appetite to have gone to a court, I wonder whether the magistrates would have laughed it out of court. To be guilty they would need to be convinced of both a guilty act and a guilty mind.
Sure, you did not have a little orange credit-card size ticket in you hand when the inspector came round, so there is a ‘guilty act’ under byelaw 18.
But a ‘guilty mind’? An intent to offend? How? Where? You paid for the tickets, you volunteered yourself to the inspector, your railcard was valid, you were polite to all parties and were given the impression that it was just a mistake and that it had been resolved on the spot. For goodness sake, you even followed the rules to the extent that you reserved spaces for the bikes!
If you had selected “e-ticket” rather than “collect before departure” from the app all would have been well. I cannot see how that error constitutes an offence.