Can I just ask, how did you respond after they had provided the additional examples of the claims in question? Did you 'admit' in the response or just ask what you owed?
Also, did they just respond with a figure and a bank account to pay to?
Most people don't return back to this forum, for reasons I believe are generally connected to some tacit admission of guilt, albeit begrudgingly, and with a high degree of reluctance. I can well believe that a lot of these people have made perfectly genuine claims on the whole, and no doubt have had a poor experience travelling with Greater Anglia, but perhaps on the odd occasion helps them to justify a more exaggerated claim, or a claim should not have been submitted. Unfortunately, if Greater Anglia spot just one or two claims which are not by the book, the "well is poisoned" so to speak, which can cause great harm to your credibility.
From what we can piece together, as long as you don't ignore them (or rile them up), yes, they respond asking you to pay an amount of money, which is punitive. It wouldn't surprise me if this could be in the high hundreds or low thousands depending on how often you've claimed, and the value of the claims. It
seems to be a case of you paying back ALL of your delay repay claims since 2019, even the genuine ones, if you want to settle out of court.
People who ignore have been directed to attend a police station for questioning under caution, relating to some fairly serious offences under the Fraud Act. We've seen actual evidence of this happening.
My advice, as always, is if you know there are some claims which are dubious, you should (must try!) to settle out of court. If that does not work, or you cannot afford to, you will probably end up with the police, and you MUST request free legal representation, even if the interview etc is "voluntary".
If your claims are all above board, it is entirely up to you whether you settle to make the problem "go away" - which isn't recommended by this forum, but your own circumstances may be that such an option makes more sense to you. If you don't settle, I'd recommend waiting for the letter from the police (if one arrives) and at that point getting some proper legal representation, but you do need to understand that however unfair it may seem, the conclusion may need to be determined by a court, and having your defence costs paid for by the prosecution (especially a Crown Prosecutor) is far, far from guaranteed, so you may still be considerably out of pocket.
Some on this forum will go into an endless spin around how unfair this is etc - but it really doesn't matter at this point. It is what it is, and unfair or not, once you're in the process, the odds are firmly stacked against you, but it is still possible to navigate a way through.
My final piece of advice is don't send angry letters to people like MPs etc, don't annoy Greater Anglia by getting yourself wound up and reacting, don't speak to the papers. Once the entire thing is over, you can go wild and tell the world and sundry how unfair it was, and if you feel it necessary, could even look at civil action. The whole thing needs to be kept nice and measured.