Pre-Court Settlement Offer - GWR

[30907]

So in the right legally. But morally wrong. I is a shame that the UK has come to this.

Exactly the reverse: the OP is morally in the wrong, on the basis of an ancient law saying "you shall not steal", but just possibly able to argue the legality from the wording of the letter.

So I guess we have come full circle then: they are being reported for their return journey (NOT the outward),

No, they are being reported ON their return journey FOR both journeys, as they held a return ticket.
It is open to the OP to argue that they didn't make the outward journey, of course, but from post #1 that would appear to fall foul of another ancient law...

 

[Romilly]

As for the amount being sought, it is made up of £175.75 for unpaid fares and an amount for costs. £175.75 looks like it could be the difference (at 2017 prices) between an undiscounted anytime return and a discounted super offpeak return. If I am right about that, GWR appear to be giving the OP credit for the amount already paid.