To the OP: my ex had a situation where she boarded a train and bought a ticket from the guard. At the end the ticket didn’t open the gate. Turns out it was the ‘wrong’ ticket she had been sold (see GG’s comment ^^^ about off peak I guess) and the inspector demanded the uplift (less than £2). The ex replied I’ve paid for a ticket you (i.e. rail company made the mistake). The inspector then called over the police…
…who couldn’t give a shit (hardly surprising really). BTW the ex is sub 5′ and hardly likely to start a fight.
The ex complained to the rail company as she was extremely radged up over the whole thing. They sent some vouchers as means of compensation.
You might try a similar tack? (not for vouchers, but recognition that their employees sometimes got OTT)