we get where you are coming from, you are entitled to the refund, you were returning off peak....but, revenue protection would not be there to screen travellers during off peak times as its utterly pointless in most scenarios.
why screen off peak travellers in off peak time? they are not losing any peak time ticket revenue?? pointless.
unless they see from data that a pertis machine has had unusually high usage that morning I cant see the point.
I don't think this issue is as widespread as you perceive , looking at available data there less than 100 pertis machines left across the whole uk...
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!