I'll be honest: I'm beginning to quite like the guy... and great to hear his sorrow is "genuine". That's important, right?
Thank you for your email and I am sorry for Tuesdays delay.
We had to cancel our 20:51 to Oxford due to a problem with the PA address system (hence why the cancellation itself wasn't announced on the train). Being a safety issue, we couldn't ignore it. Unfortunately, there was no replacement train we could step up into service and therefore we did have to ask customers to wait for the next service.
I appreciate this meant that the train you travelled on was crowded and I am genuinely sorry for yet another disappointing journey.