HB, that applies to penalty fares, where the penalty is the higher of £20 or twice the single fare, so although it involves the “peak vs. Off-peak” issue, I’m not sure it applies to the OP’s situation.
As many as 10,000 rail travellers have been overcharged after being caught and penalised for not having a valid ticket.
The Rail Delivery Group (RDG), the industry body that represents private train operators as well as Network Rail, has admitted that tickets inspectors have overcharged fare-dodgers to the tune of tens of thousands of pounds after rail companies failed to implement a rule change introduced in April 2018.
Don't touch them owe me £500 since January 2019 make excuse after excuse. Seem they always have software problems sending money out. Keep saying they will call back or email nothing been chasing it now for 6 mths the phone staff always have the same banter we will chase it up and get back to you then nothing!