Hi Saj,
That’s a bit of a difficult one. Can you give me more info (date and time) and I’ll try and find out what was happening then. I’m disappointed that they appear to be changing their story. Strikes must be putting a toll on the amount of calls, but that’s no excuse for giving misleading information.
If there was a strike then you’d be expected to know what was running and plan accordingly, therefore they would not give refunds in that situation. However, if there was a temporary reason why the Overground wasn’t running then I would hope that they’d offer a refund down to the fare for the journey you actually made as a gesture of goodwill.
I can’t say which way they’ll go, but if I can find out the reason then I suggest you write an email asking them to reconsider.